Health status, neighborhood socioeconomic context, and premature mortality in the United States: The National Institutes of Health-AARP Diet and Health Study

Objectives. We examined whether the risk of premature mortality associated with living in socioeconomically deprived neighborhoods varies according to the health status of individuals.Methods. Community-dwelling adults (n = 566 402; age = 50–71 years) in 6 US states and 2 metropolitan areas participated in the ongoing prospective National Institutes of Health–AARP Diet and Health Study, which began in 1995. We used baseline data for 565 679 participants on health behaviors, self-rated health status, and medical history, collected by mailed questionnaires. Participants were linked to 2000 census data for an index of census tract socioeconomic deprivation. The main outcome was all-cause mortality ascertained through 2006.Results. In adjusted survival analyses of persons in good-to-excellent health at baseline, risk of mortality increased with increasing levels of census tract socioeconomic deprivation. Neighborhood socioeconomic mortality disparities among persons in fair-to-poor health were not statistically significant after adjustment for demographic characteristics, educational achievement, lifestyle, and medical conditions.Conclusions. Neighborhood socioeconomic inequalities lead to large disparities in risk of premature mortality among healthy US adults but not among those in poor health.Research dating back to at least the 1920s has shown that the United States has experienced persistent and widening socioeconomic disparities in premature mortality over time.^1–5 However, it has been unclear whether socioeconomic inequalities affect the longevity of persons in good and poor health equally. Socioeconomic status (SES) and health status are interrelated,^6–8 and both are strong independent predictors of mortality.⁹ Low SES is associated with greater risk of ill health and premature death,^{1–5,8,10–13} partly attributable to disproportionately high prevalence of unhealthful lifestyle practices^10,14,15 and physical and mental health conditions.^13,16 Correspondingly, risk of premature mortality is higher in poor than in more affluent areas.^16,17 Although the association between neighborhood poverty and mortality is independent of individual-level SES,^17,18 aggregation of low-SES populations in poor areas may contribute to variations in health outcomes across neighborhoods. Conversely, economic hardships resulting from ill health may lead persons in poor physical or mental health to move to poor neighborhoods.¹⁹ This interrelatedness may create spurious associations between neighborhood poverty and mortality.Although previous studies have found that the risk of premature death associated with poor health status varies according to individuals'' SES,^20,21 no published studies have examined whether the relative risks for premature mortality associated with living in neighborhoods with higher levels of socioeconomic deprivation vary by health status of individuals. Clarifying these relationships will inform social and public health policies and programs that aim to mitigate the health consequences of neighborhood poverty.^22,23We used data from a large prospective study to examine whether the risk of premature mortality associated with neighborhood socioeconomic context differs according to health status at baseline and remains after adjustment for person-level risk factors for mortality, such as SES, lifestyle practices, and chronic medical illnesses.     

Association of Perceived Neighborhood Safety on Body Mass Index

Objectives. We sought to determine whether there is an association between perceived neighborhood safety and body mass index (BMI), accounting for endogeneity.Methods. A random sample of 2255 adults from the Los Angeles Family and Neighborhood Survey 2000–2001 was analyzed using instrumental variables. The main outcome was BMI using self-reported height and weight, and the main independent variable was residents’ report of their neighborhood safety.Results. In adjusted analyses, individuals who perceived their neighborhoods as unsafe had a BMI that was 2.81 kg/m² (95% confidence interval [CI] = 0.11, 5.52) higher than did those who perceived their neighborhoods as safe.Conclusions. Our results suggest that clinical and public health interventions aimed at reducing rates of obesity may be enhanced by strategies to modify the physical and social environment that incorporate residents’ perceptions of their communities.Obesity is a major public health problem^1–5 that contributes to poor quality of life; increased incidence of diabetes, cardiovascular disease, and other chronic conditions; and higher mortality rates.⁵ During the last decade, population-based strategies to reduce obesity have emphasized modification of physical and social environments, which may be particularly important in disadvantaged communities. Low neighborhood socioeconomic status (SES),⁶ a higher proportion of Black and Latino residents,^7–10 barriers in the built environment (e.g., fewer places to walk),^11,12 lack of access to supermarkets or fresh fruits and vegetables,^6,13,14 and a higher density of fast food restaurants¹⁵ are all characteristics of residential environments associated with obesity. Research also suggests that low levels of collective efficacy (a perception of mutual trust and willingness to help each other)¹⁶ are associated with adolescent obesity. However, the mechanisms through which neighborhood social, economic, and physical characteristics lead to weight gain and obesity are not well characterized.Perceived neighborhood safety is a mechanism through which neighborhood characteristics may influence obesity. Residence in a neighborhood perceived as unsafe may contribute to obesity in a number of ways, including increased secretion of stress hormones,^17–19 lower rates of walking or other outdoor physical activity,^20–28 and higher rates of stress-related eating.^29–32 Perceived safety may reflect the physical, social, and resource characteristics of neighborhoods. For example, residents may perceive a neighborhood to be unsafe if supermarkets and retailers that sell fresh fruits and vegetables are unwilling to locate in their neighborhoods, or if fast food restaurants and stores that sell low-cost, calorie-dense foods tend to locate in their neighborhoods.^33–35 Yet, the limited literature on relations between perceived safety and body weight is mixed. One study found that mothers with young children, residing in large cities, and perceiving their neighborhoods as unsafe were more likely to be obese,³⁶ and another study found no association between perceived safety and obesity.³⁷ Similarly, in the larger body of literature on neighborhood safety and physical activity, some studies found an association of perceived neighborhood safety with physical activity levels,^20–26 although other analyses showed no such relationship,^38–42 suggesting a more complex etiology.We hypothesized that 1 reason for the inconsistent findings in these previous analyses—all of which were cross-sectional—is endogeneity bias, that is, the possibility that the findings from these studies may have been influenced by either reverse causality^36,43 or unmeasured neighborhood or individual characteristics influencing both perceived neighborhood safety and obesity. For example, reverse causality may occur if larger individuals, believing nobody would attack them because of their size, feel safer, or if larger individuals, being less agile and less physically fit and believing they cannot protect themselves, feel less safe. To address the possibility of endogeneity from reverse causality or unmeasured neighborhood or individual characteristics, we studied the association between perceived neighborhood safety and obesity in a population-based, geographically sampled cohort of residents in Los Angeles County, California. We used 2-stage least squares regression, a special case of an instrumental variables analysis that is a method developed to produce statistically consistent estimates when the covariate of interest is potentially endogenous. To our knowledge, no studies to date have used instrumental variables analysis to assess the relationship between neighborhood safety and obesity.     

Neighborhoods and Chronic Disease Onset in Later Life

Objectives. To strengthen existing evidence on the role of neighborhoods in chronic disease onset in later life, we investigated associations between multiple neighborhood features and 2-year onset of 6 common conditions using a national sample of older adults.Methods. Neighborhood features for adults aged 55 years or older in the 2002 Health and Retirement Study were measured by use of previously validated scales reflecting the built, social, and economic environment. Two-level random-intercept logistic models predicting the onset of heart problems, hypertension, stroke, diabetes, cancer, and arthritis by 2004 were estimated.Results. In adjusted models, living in more economically disadvantaged areas predicted the onset of heart problems for women (odds ratio [OR] = 1.20; P < .05). Living in more highly segregated, higher-crime areas was associated with greater chances of developing cancer for men (OR = 1.31; P < .05) and women (OR = 1.25; P < .05).Conclusions. The neighborhood economic environment is associated with heart disease onset for women, and neighborhood-level social stressors are associated with cancer onset for men and women. The social and biological mechanisms that underlie these associations require further investigation.Currently, 8 out of 10 older adults in the United States have at least 1 chronic condition.¹ Reports of many common chronic conditions, such as heart disease, arthritis, diabetes, and some cancers, have been increasing, as have the costs associated with their treatment.^2,3 Although the etiology of such conditions varies greatly, a rapidly growing literature has documented associations between characteristics of the neighborhoods in which older people live and late-life morbidity.The most studied neighborhood feature in this context is economic disadvantage. Studies have established that living in economically deprived areas is associated with higher risks of heart disease,^4–11 stroke,^12–14 hypertension,^6,15,16 and a greater number of chronic conditions,^17,18 but lower cancer incidence.^19–21 These effects, which appear to be greater for women than for men,^{6,9–11,19,22} often attenuate but are not completely eliminated after individual-level factors are taken into account. Numerous mechanisms have been postulated as underlying the linkage between economic deprivation and chronic conditions. In reviewing cardiovascular disease mechanisms, for example, Diez Roux discussed how social and physical aspects of poor neighborhoods may influence individual risk factors (e.g., physical activity, diet, smoking, and the ability to recover from stress), which in turn may influence more proximate biological risk factors (e.g., blood pressure, diabetes, body mass index, blood lipids, and inflammation).²³Recently, the literature has begun to address noneconomic features of neighborhoods, such as the social and built environments, and their relation to health in later life.^{16,20,24–28} The social environment refers to relations among people living in a particular area and encompasses concepts such as connectedness to and similarity with neighbors and social disorder. The built environment refers to factors related to man-made elements including housing quality, businesses, street design, pollution, and crowding. Like the linkage between poor neighborhoods and cardiovascular disease, the relationship between the social and built environments and later-life morbidity is likely to be complex, operating through physiologic stress as well as health behaviors such as physical activity and diet and access to providers. However, measures of the social and built environment have typically been absent from analyses that include measures of economic disadvantage, thus making it difficult to sort out these influences.More generally, conclusions that can be drawn from the growing number of studies devoted to neighborhood influences on late-life health remain limited in several respects. First, most studies highlight the relationship between a single neighborhood facet and 1 chronic condition. This approach precludes comparisons across conditions, and also limits interpretation, because aspects of the economic, social, and built environment are likely to be correlated. Second, only about one third of studies to date have examined disease incidence,^{4,5,10,11,15,20,22,29,30} whereas remaining studies have focused on prevalence. The latter confounds influences of the neighborhood on disease onset with its effects on survival and therefore provides only limited insight into disease etiology. Third, with few exceptions,^17,18 studies focusing on the United States have drawn data from a limited number of communities, thus the generalizability of the results is uncertain. Fourth, indicators of individual-level circumstances often have been quite limited; consequently, the effect of neighborhood-level factors may be confounded by unmeasured individual-level factors. Fifth, selection into neighborhoods along health dimensions may bias findings, yet studies to date have not attempted to control for circumstances that may act as a proxy for neighborhood exposures earlier in life. Finally, despite evidence that chronic disease etiology and expression may differ for older men and women,^31–33 gender-specific investigations have been the exception rather than the norm.We aimed to enhance this literature by adopting a richer characterization of the neighborhood that draws on previously validated scales reflecting the economic, social, and built neighborhood environment. We explored associations between these scales and the reported onset of 6 of the most commonly reported late-life conditions: hypertension, heart problems, stroke, diabetes, cancer, and arthritis. We hypothesized that all 3 domains—the economic, social, and built environments—would contribute to increased risks of chronic conditions in later life. To explore these hypotheses, we used a large, nationally representative sample of US adults aged 55 years or older from the Health and Retirement Study (HRS).³⁴ The HRS includes excellent contemporaneous measures of income and assets, as well as retrospective measures of health and wealth earlier in life. We therefore were better able than previous studies to isolate the contribution of neighborhood-level socioeconomic components. Moreover, the large sample sizes allowed us to stratify the analyses for men and women.     

Racial residential segregation and low birth weight in Michigan's metropolitan areas

Objectives. We examined the influence of racial residential segregation, independent of neighborhood economic factors, on the overall and specific etiological risks of low birth weight.Methods. We geocoded all singleton births in Michigan metropolitan areas during 2000 to census tracts. We used hierarchical generalized linear models to investigate the association between low birth weight (< 2500 g) and neighborhood-level economic and racial segregation, controlling for individual and neighborhood characteristics. We analyzed competing risks of the 2 etiologies of low birth weight: intrauterine growth restriction and preterm birth.Results. Living in a Black segregated area was associated with increased odds (odds ratio [OR] = 1.15; 95% confidence interval [CI] = 1.03, 1.29; P < .05) of low birth weight after adjusting for individual- and tract-level measures. The analysis suggested that the association between low birth weight and racial segregation was attributable primarily to increased risk of intrauterine growth restriction (OR = 1.19; 95% CI = 1.03, 1.37; P < .05).Conclusions. Odds of low birth weight are higher in racially segregated Black neighborhoods in Michigan''s metropolitan areas, independent of economic factors. The association appears to operate through intrauterine growth restriction rather than preterm birth.As the leading cause of death among non-Hispanic Black infants and second-leading cause of death among non-Hispanic White infants, complications related to short gestation and low birth weight represent a significant clinical and public health issue.^1–3 Low birth weight also leads to long-term health consequences through increased rates of childhood and adult chronic diseases.^3–6 Racial disparities in rates of low birth weight have persisted even as total infant mortality has declined and prenatal care utilization among women of color has increased.^1–3 Because differences in individual-level risk factors cannot completely explain the differences in outcomes for White and Black mothers,^3,7 researchers have begun investigating contextual influences on racial disparities in birth outcomes.^3,8Racial segregation is a contextual factor that might contribute to racial disparities in low birth weight by isolating Blacks from the resources and opportunities found more frequently in White communities.^9–13 Residents in Black segregated neighborhoods accumulate less home equity,^14,15 have decreased access to quality primary education,¹⁶ and are exposed to greater residential and economic instability than are residents of nonsegregated communities.⁹ The accumulation of disadvantages in racially isolated neighborhoods could lead to negative birth outcomes for women by limiting opportunities associated with improved health (e.g., educational opportunities or access to quality medical care) and by exposing them to increased stress from neighborhood-level factors.Evidence from a small number of studies suggests that low birth weight is associated with racial residential segregation.^17–24 With few exceptions,^17,25,26 studies link metropolitan-level segregation or the percentage of Black residents in a community to low birth weight. However, because isolation is inherently spatial, to understand how the racial isolation of an individual mother''s neighborhood affects her pregnancy outcomes, isolation is most appropriately measured by considering her neighborhood along with its immediate surroundings (e.g., bordering neighborhoods) rather than by the metropolitan area or a single neighborhood.¹⁷Some authors have argued that racial segregation simply serves as a proxy for economic segregation.^27,28 By contrast, we posit that racial segregation is a distinct form of neighborhood-level disadvantage that presents an increased risk for low birth weight beyond that caused by economic segregation. Sociologists have shown that, even in the presence of economic segregation, the circumstances of racially segregated Black neighborhoods differ from those of White neighborhoods at similar socioeconomic levels.^29–32 This means that although residents of Black middle-class neighborhoods may live in residential areas that are separate from poor Black neighborhoods, they have greater exposure than do middle-class Whites to negative contextual factors and have fewer resources in their vicinity. This also suggests that any attempt to distinguish between the effects of racial and economic segregation on low birth weight requires that economic segregation also be measured spatially, taking a mother''s neighborhood and its immediate surroundings into account.It is also important to consider that the drivers of low birth weight—preterm birth and intrauterine growth restriction—have distinct physiological mechanisms.^33–35 Assessing the degree to which racial isolation is associated with each can provide important insight into the etiological mechanisms relating racial segregation to low birth weight. Spontaneous preterm birth is commonly precipitated by an infection,^36–40 which could be associated with racial segregation if, for instance, racial segregation reduces access to quality care.²⁵ Intrauterine growth restriction, on the other hand, typically stems from a chronic deficiency in oxygen and nutrient delivery to the fetus.^41–46 Chronic stress associated with the circumstances of racially isolated neighborhoods might affect placental vasculature function, creating an oxygen–nutrient insufficiency that leads to intrauterine growth restriction.⁴⁷ We know of no research that has considered the competing risks of growth restriction and preterm birth in the relationship of neighborhood environments with low birth weight.We examined births to mothers living in Michigan metropolitan areas to ascertain whether neighborhood racial segregation was associated with low birth weight independent of economic factors. We explicitly captured the spatial nature of both racial and economic segregation through a localized segregation index. We also analyzed the degree to which racial segregation was associated with different etiologies of low birth weight.     

Neighborhood Characteristics and Change in Depressive Symptoms Among Older Residents of New York City

Objectives. We investigated the relationship between the depressive symptoms of older adults over time and the characteristics of the neighborhoods in which they live.Methods. We surveyed a random sample of 1325 New York City residents aged 50 years or older in 2005 and conducted 808 follow-up interviews in 2007. We assessed the compositional characteristics of the respondents'' neighborhoods at a census-tract level and determined the relationships between these characteristics and changes in respondents'' depressive symptoms.Results. In multivariable models that adjusted for individual-level covariates including income, a range of neighborhood characteristics predicted worsening depressive symptoms. Factor analysis suggested that these characteristics operated in 3 clusters: neighborhood socioeconomic influences, residential stability, and racial/ethnic composition, with positive neighborhood socioeconomic influences being significantly protective against worsening symptoms. Life stressors, personality trait neuroticism, African American race, and daily baseline contact with social networks were also associated with worsening symptoms.Conclusions. An older adult''s neighborhood of residence is an important determinant of his or her mental health. Those making efforts to improve mental health among the elderly need to consider the role of residential context in improving or impairing mental health.Depression is an important cause of morbidity in the general community.¹ The prevalence of depression is high among elderly persons, and longitudinal studies have found modest increases in depressive symptoms with age.^2–4 The incidence of depression peaks in early adult life, but there appears to be a secondary peak in incidence among people in their 50s, suggesting that the transition to older age may present specific risks for depression.⁵ Depression is associated with significant disability among older adults and may place their functional independence at risk.⁶ At least 1 longitudinal study has also suggested that older African Americans may be at increased risk of symptoms of depression compared with older White adults.⁷Although a number of individual-level factors are known to increase the risk of depression,^8–10 it has long been thought that the physical and social environments in which people live may also influence their mental health.^11–13 The environment may play a particularly important role in the mental health of older adults, who, compared with younger adults, are more likely to spend time in their neighborhood of residence, more likely to suffer from disabilities that may be exacerbated by their environments,¹⁴ and are more vulnerable to threats to their safety.^15–17A number of theories have been proposed to explain this association between neighborhood characteristics and depression. Researchers have drawn on systemic theory to propose that neighborhoods characterized by higher levels of poverty and residential instability have lower levels of social cohesion and lower levels of control over deviant social networks.^18,19 The concomitant lack of social order may contribute to low levels of trust, which would impede collaborative efforts to control crime and reduce neighborhood disorder.²⁰ High levels of crime may generate higher levels of fear and stress, as could the deteriorating building conditions and high levels of physical disorder associated with disadvantaged neighborhoods.^20,21 In contexts of social isolation and limited social organization, residents may not benefit from the social networks necessary to buffer them from the stressors they face on a daily basis.²²These theories about the influence of the neighborhood context on collective and individual sources of stress agree with the “differential vulnerability” hypothesis and with social stress theory, both of which posit that environments can influence health by increasing the likelihood of personal stress events such as unemployment or traumatic events, or by providing resources to cope with such stressors.^23–26 Studies using multilevel analytic methods that can account for both individual-level and neighborhood-level effects suggest that neighborhood-level characteristics such as affluence, disadvantage, inequality, and residential stability have a significant impact on physical health, even after accounting for individual-level factors.^27–30 However, research into their possible influence on mental health has been more limited.Cross-sectional studies using multilevel approaches have suggested that symptoms of depression are more prevalent in residents of disadvantaged neighborhoods^31–33 and that this association may be stronger in neighborhoods having less residential turnover^34,35 or higher population density.³⁶ Similar associations have been observed among older adults, for whom living in a neighborhood that is poor or has few elderly people has been associated with higher levels of depressive symptoms, after accounting for individual vulnerabilities.³⁷ The presence of stress-buffering support systems has been associated with lower levels of depression in cross-sectional research, whereas low levels of social support in neighborhoods with high social isolation were related to higher depression levels.^38,39 However, other research has failed to replicate these findings.⁴⁰ Furthermore, the cross-sectional nature of this research means that even positive studies cannot exclude the possibility that the observed relationships simply reflect a tendency for depressed individuals to become disadvantaged or to live in disadvantaged neighborhoods.Longitudinal research can better explore the causal mechanisms behind these relationships, but there have been few prospective studies in this field. A study of individuals who were screened for an HIV prevention intervention found that perceptions of neighborhood characteristics predicted change in depressive symptoms 9 months later.⁴¹ The Alameda County Study found that living in a high-poverty area was associated with worse health status and more symptoms of depression; however, this association was lost when all individual-level covariates were included in multivariable analysis.⁴² In previous research conducted by members of our own team, we identified a significant association between incident depression and neighborhoods classified as low socioeconomic status, even after adjusting for individual income, adverse life events, and educational status.⁴³ This kind of prospective research, although suggestive, has often been weakened by reliance on perceived neighborhood characteristics, limitations of the measures used, or absence of information on possible confounders.To overcome these limitations, we examined the relationship between characteristics of the neighborhood of residence of older adults and symptoms of depression using longitudinal data from the New York City Neighborhood and Mental Health in the Elderly Study (NYCNAMES). We hypothesized that neighborhood socioeconomic status may either exacerbate or ameliorate the stressors confronting participants, thereby influencing levels of depression symptoms over the study period, even after accounting for key individual-level factors. We used information from the 2000 US Census to characterize neighborhoods, and we aggregated these characteristics into dimensions that might shed light on the mechanisms underlying observed relationships.     

Neighborhood social disorganization and the acquisition of trichomoniasis among young adults in the United States

Objectives. We examined relationships between neighborhood social disorganization and trichomoniasis among young US adults.Methods. We employed multilevel logistic regression modeling with secondary data from wave III of the National Longitudinal Study of Adolescent Health (2001–2002). The dependent variable—trichomoniasis—was measured via urine testing. The measures for neighborhood social disorganization were derived from the 2000 US Census—racial and ethnic composition, concentrated poverty, and residential instability. The sample comprised 11 370 individuals across 4912 neighborhoods.Results. Trichomoniasis was more likely in neighborhoods with higher concentrations of Black residents (adjusted odds ratio [AOR] = 1.16; 95% confidence interval [CI] = 1.03, 1.30). However, this association was mediated by neighborhood concentrated poverty. Furthermore, young adults who lived in neighborhoods with higher concentrations of poverty were significantly more likely to have trichomoniasis (AOR = 1.25; 95% CI = 1.07, 1.46). Neither immigrant concentration nor residential instability was significantly associated with trichomoniasis.Conclusions. These findings strengthen the evidence that neighborhood structural conditions are associated with individual sexually transmitted infection (STI) acquisition. Research is needed to explore the mechanisms through which these conditions influence STI. In addition, STI-prevention programs that include structural interventions targeting neighborhood disadvantage are needed.Adolescents and young adults are at increased risk for sexually transmitted infections (STIs) because of a complex interplay of biological, behavioral, and developmental factors.¹ Nearly half of all STIs diagnosed in the United States annually are among adolescents and young adults^1,2 despite national priority goals aimed at reducing infection rates.³ Trichomoniasis, a common and easily curable STI,¹ is of increasing concern because the infection facilitates HIV acquisition and transmission through mucosal inflammation of the genital tract and alterations in the innate immune response. ^4-7 The infection is caused by the protozoa, Trichomonas vaginalis, and is typically transmitted via penis-to-vagina or vulva-to-vulva contact.¹ Infected persons are often asymptomatic or experience only mild symptoms,¹ which can hinder early detection and treatment and increase the risk of STIs and HIV.In the United States, the prevalence of trichomoniasis is difficult to ascertain because routine screening currently is not recommended nor is the reporting of positive results required.^1,4 According to urine assay data from the National Longitudinal Study of Adolescent Health (Add Health), the prevalence of trichomoniasis among the young adult population in 2001–2002 was approximately 2.3%.⁷ The study also found that women were at greater risk than were men (2.8% vs 1.7%) as were non-Hispanic Black (6.9%) and Latino (2.1%) youths compared with their non-Hispanic White peers (1.2%).⁷ In other studies of adult women, individual risk factors for trichomoniasis included poverty, lower education, douching, non-Hispanic Black race/ethnicity, and greater numbers of lifetime sexual partners.^8,9 Among clinic samples of adolescent women, research found trichomoniasis to be associated with older male sexual partners, casual sexual activity, marijuana use, and delinquency.¹⁰However, to date, no studies have examined the role of the broader structural context in shaping trichomoniasis risk, despite theory and previous STI research suggesting that the neighborhood environment may play a role. According to social disorganization theory,^11–14 key indicators of neighborhood structural disadvantage (i.e., racial/ethnic composition, concentrated poverty, and residential instability) influence health outcomes by weakening social ties, reducing access to institutional resources, and limiting exposure to positive role models, conventional social norms, and collective efficacy. Findings from previous research examining other STIs support the hypothesis that neighborhood contexts influence STI prevalence. For example, with respect to racial and ethnic composition, studies have found that gonorrhea rates were higher in cities and neighborhoods with greater proportions of Black residents.^15,16 Furthermore, in an analysis of Chicago neighborhoods, the incidence rates of gonorrhea and chlamydia were higher for neighborhoods in which more than 60% of the residents were Black compared with those in which more than 60% of residents were Hispanic, which suggests that segregated Hispanic ethnic enclaves may be protective of STI compared with segregated Black communities.¹⁷ Researchers hypothesize that the residential segregation of Black communities has contributed to the pervasive Black-White disparities in STI through discrimination processes, which in turn has led to greater concentration of poverty, lower male-to-female gender ratios due to the disproportionate incarceration and mortality of Black men, and closed, racially segregated sexual networks that facilitate the transmission of infection.^18–20In addition, the role of community poverty in shaping STI risk has been examined extensively and found to be positively associated with rates of chlamydia, gonorrhea, syphilis, and HIV in cross-sectional^{15,17,21–23} and longitudinal analyses.¹⁶ Other socioeconomic factors, such as unemployment^17,24 and lower educational attainment,^16,17 have also been linked to higher rates of chlamydia and gonorrhea. Research on the effects of residential instability on STI is limited, but the single study that examined these relationships found greater residential instability was associated with fewer self-reported STIs among a national sample of adolescents.²⁴ Depending on the context, perhaps residential instability could increase STI risk by disrupting social support ties and informal social control measures or reduce STI risk by dispersing closed sexual networks that facilitate infection transmission.Although the aforementioned studies have illustrated links between neighborhood social disorganization and a variety of STIs, limitations exist. First, the majority have been ecological studies, in which the outcomes were measured as community STI rates and no adjustment was made for potential confounding relationships with individual-level data.^{15–17,21–23} Consequently, inferences can be made only about the community, and individual variation in the outcome cannot be ascertained.²⁵ Second, although 1 study examined individual STI, the measure was based on self-report,²⁴ which potentially increases bias because of underreporting as well as unrecognized or undiagnosed infection. In addition, the study only focused on STI in general, which could limit our understanding of unique relationships with specific infectious organisms. Third, data sources of previous research tend to be at local or state levels,^{15–17,21–23} which limits external validity of the findings. Therefore, the purpose of our research was to examine relationships between neighborhood social disorganization and trichomoniasis among young adults in the United States. Our research builds on previous studies in 3 significant ways: (1) we examined multiple levels of analysis, which enabled us to simultaneously examine the independent relationships between individual and neighborhood variables and individual acquisition of trichomoniasis, (2) we examined a more refined measure of STI through the use of urine screening, and (3) we examined data from a large national data set—Add Health.     

Neighborhood Context and Infant Birthweight Among Recent Immigrant Mothers: A Multilevel Analysis

Objectives. We compared the influence of the residential environment and maternal country of origin on birthweight and low birthweight of infants born to recent immigrants to urban Ontario.Methods. We linked delivery records (1993–2000) to an immigration database (1993–1995) and small-area census data (1996). The data were analyzed with cross-classified random-effects models and standard multilevel methods. Higher-level predictors included 4 independent measures of neighborhood context constructed by factor analysis and maternal world regions of origin.Results. Births (N = 22 189) were distributed across 1396 census tracts and 155 countries of origin. The associations between neighborhood indices and birthweight disappeared after we controlled for the maternal country of origin in a cross-classified multilevel model. Significant associations between world regions and birthweight and low birthweight persisted after we controlled for neighborhood context and individual characteristics.Conclusions. The residential environment has little, if any, influence on birthweight among recent immigrants to Ontario. Country of origin appears to be a much more important factor in low birthweight among children of recent immigrants than current neighborhood. Findings of neighborhood influences among recent immigrants should be interpreted with caution.Socioeconomic disparities in birth outcomes are well documented,^1–3 even in countries with universal access to health care,^4,5 such as Canada. An increasing body of literature, including several multilevel studies, suggests that context affects birth outcomes, particularly neighborhood influences in predominantly urban areas.^6–16 Little is known, however, about neighborhood influences among immigrants.^15,17–19There are theoretical and practical reasons to explore this issue. It has been suggested that exposure to neighborhoods may take some time to affect human health.²⁰ Even if neighborhood influences are detected among the offspring of recent immigrant women exposed to neighborhoods during their entire pregnancy, a life-course perspective suggests that early life experiences and premigration exposures may still affect birth outcomes of migrants in the new country.^19,21 The maternal country of origin thus constitutes another relevant context to be considered when analyzing differences in birthweight among recent immigrants, because substantial differences in birthweight have been reported by geographical region and nativity status.^22–24 It is important to clarify the role of the pre- and postmigration exposures, because the proportion of live births to immigrant women has been showing an upward trend during recent decades in several industrialized countries.^24–27We compared the influence of the residential environment at the time of delivery with that of the maternal country of origin on birthweight and the proportion of low birthweights among infants born to women who recently immigrated to Canada and settled in Ontario census metropolitan areas from 1993 to 1995. We hypothesized that the maternal country of origin would have a greater effect on birthweight than would the residential environment in which immigrants currently resided in urban Ontario.     

Alcohol advertising at Boston subway stations: an assessment of exposure by race and socioeconomic status

Objectives. We investigated the frequency of alcohol ads at all 113 subway and streetcar stations in Boston and the patterns of community exposure stratified by race, socioeconomic status, and age.Methods. We assessed the extent of alcohol advertising at each station in May 2009. We measured gross impressions and gross rating points (GRPs) for the entire Greater Boston population and for Boston public school student commuters. We compared the frequency of alcohol advertising between neighborhoods with differing demographics.Results. For the Greater Boston population, alcohol advertising at subway stations generated 109 GRPs on a typical day. For Boston public school students in grades 5 to 12, alcohol advertising at stations generated 134 GRPs. Advertising at stations in low-poverty neighborhoods generated 14.1 GRPs and at stations in high-poverty areas, 63.6 GRPs.Conclusions. Alcohol ads reach the equivalent of every adult in the Greater Boston region and the equivalent of every 5th- to 12th-grade public school student each day. More alcohol ads were displayed in stations in neighborhoods with high poverty rates than in stations in neighborhoods with low poverty rates.Excessive alcohol use is the third-leading lifestyle-related cause of death in the United States.¹ Immediate health risks include unintentional injuries,² violence,^2,3 risky sexual behaviors,^4,5 miscarriage and stillbirth among pregnant women,^6,7 fetal alcohol syndrome,⁷ and alcohol poisoning.⁸ Long-term health risks include neurological,^9,10 cardiovascular,^11,12 and psychiatric problems,¹³ as well as an increased risk of cancer,^12,14 liver disease,^12,15,16 and pancreatitis.^12,17,18 Excessive alcohol use is also linked to a variety of social problems, including increased unemployment¹⁹ and frequency of violent crime and incarceration.^20,21 Drinking among underage youths is increasing.^22–25 Excessive alcohol use also has economic consequences. Alcohol-related health care utilization (e.g., motor vehicle crashes, fires), productivity losses, social welfare (e.g., food stamps), and criminal justice cost the United States an estimated $184.6 billion in 1998 alone.^12,26Alcohol advertising has historically been linked to increased consumption of alcohol in youths,^25,27–31 and a more recent study also shows an increase in consumption by adults.³² These data come from studies of advertising in a variety of media, including television, music video, public transit, and outdoor advertising.^25–31 Alcohol is disproportionately advertised in low-income neighborhoods^33,34 and in neighborhoods with a high proportion of racial and ethnic minorities.^32,34–36Studies have shown that people of color experience poorer health outcomes and shorter life expectancies than do Whites.³⁷ Individuals of lower socioeconomic status also have been found to have higher morbidity and mortality and more risk factors for heart disease and stroke than do people of higher socioeconomic status.³⁸ Minorities are more likely to live in poverty, which exacerbates the negative consequences of alcohol use.³⁹ Because racial and ethnic minorities and individuals of lower socioeconomic status are at a higher risk for poor health and have been identified as targets of alcohol advertising, it is critical that advertising policies change to protect these disadvantaged groups. Hackbarth et al. suggest that reducing alcohol consumption among disadvantaged groups through community intervention, such as banning alcohol advertising, would be one way to eliminate such health disparities.³⁶In 2007 Kwate et al. determined that Black neighborhoods in New York City had more advertising space than White neighborhoods and that these spaces were disproportionately used to market alcohol and tobacco products.³⁵ However, they did not find a significant relationship between median income and ad density, which suggests that relative affluence did not protect Black neighborhoods from targeted outdoor advertising.Advertising on public transportation has received little attention in the literature. In 2007, a report issued by the Marin Institute documented the advertising practices of 20 public transit agencies nationwide. The report found that 2 major cities, Boston, Massachusetts and New York City, lagged far behind other cities that had policies in place to protect children from alcohol advertising.²⁵ Chicago, Illinois; Los Angeles, California; San Francisco, California; Washington, DC; and other places explicitly prohibit alcohol advertising on public transit systems. For example, San Francisco imposes a $5000 per day fine for violating advertising policies.²⁵ By contrast, the Massachusetts Bay Transit Authority (MBTA), which serves the Boston area, has no such restrictions against alcohol advertising, although it claims to prohibit all “adult-oriented goods and services.” The MBTA bans advertising that features tobacco, violence, or nudity because they are considered inappropriate for viewing by minors.²⁵ It is disturbing that one of the largest cities in the United States has not yet adopted stricter policies to protect its riders from potentially harmful alcohol ads.In 2009, Nyborn et al. studied the frequency of alcohol advertising on MBTA train cars and found that alcohol advertisers were able to reach the equivalent of nearly half of all transit passengers each day.⁴⁰ These data showed that roughly 315 000 people, or 11% of the entire adult population in the greater Boston area (Suffolk, Middlesex, and Norfolk counties; total 2008 population = 2 841 374⁴¹) may be exposed to alcohol ads on the MBTA train lines alone. However, that study focused on ads on moving trains and did not consider the frequency of alcohol ads at train stations and how this frequency might differ between neighborhoods. We expanded the focus to include train stations to investigate whether alcohol advertising targeted particular socioeconomic or racial/ethnic groups.We aimed to (1) quantify exposure to alcohol advertising at MBTA train stations among adults in the greater Boston area and among Boston public school students in grades 5 to 12 and (2) compare the frequency of alcohol ads in different MBTA train stations to determine whether minority or poor populations were disproportionately exposed.     

Impact of individual-, environmental-, and policy-level factors on health care utilization among US farmworkers

Objectives. We examined individual-, environmental-, and policy-level correlates of US farmworker health care utilization, guided by the behavioral model for vulnerable populations and the ecological model.Methods. The 2006 and 2007 administrations of the National Agricultural Workers Survey (n = 2884) provided the primary data. Geographic information systems, the 2005 Uniform Data System, and rurality and border proximity indices provided environmental variables. To identify factors associated with health care use, we performed logistic regression using weighted hierarchical linear modeling.Results. Approximately half (55.3%) of farmworkers utilized US health care in the previous 2 years. Several factors were independently associated with use at the individual level (gender, immigration and migrant status, English proficiency, transportation access, health status, and non-US health care utilization), the environmental level (proximity to US–Mexico border), and the policy level (insurance status and workplace payment structure). County Federally Qualified Health Center resources were not independently associated.Conclusions. We identified farmworkers at greatest risk for poor access. We made recommendations for change to farmworker health care access at all 3 levels of influence, emphasizing Federally Qualified Health Center service delivery.US farmworkers face significant disease burden¹ and excessive mortality rates for some diseases (e.g., certain cancers and tuberculosis) and injuries.² Disparities in health outcomes likely stem from occupational exposures and socioeconomic and political vulnerabilities. US farmworkers are typically Hispanic with limited education, income, and English proficiency.³ Approximately half are unauthorized to work in the United States.³ Despite marked disease burden, health care utilization appears to be low.^1,4–9 For example, only approximately half of California farmworkers received medical care in the previous year.⁶ This rate parallels that of health care utilization for US Hispanics, of whom approximately half made an ambulatory care visit in the previous year, compared with 75.7% of non-Hispanic Whites.¹⁰ Disparities in dental care have a comparable pattern.^6,8,11,12 However, utilization of preventive health services is lower for farmworkers^5,7,13,14 than it is for both US Hispanics and non-Hispanic Whites.^15,16Farmworkers face numerous barriers to health care^1,4,17: lack of insurance and knowledge of how to use or obtain it,^6,18 cost,^{5,6,12,13,18–20} lack of transportation,^{6,12,13,19–21} not knowing how to access care,^6,18,20,21 few services in the area or limited hours,^12,20,21 difficulty leaving work,¹⁹ lack of time,^5,13,19 language differences,^6,8,18–20 and fear of the medical system,¹³ losing employment,⁶ and immigration officials.²¹ Few studies have examined correlates of health care use among farmworkers. Those that have are outdated or limited in representativeness.^5,7,14,22,23 Thus, we systematically examined correlates of US health care use in a nationally representative sample of farmworkers, using recently collected data. The sampling strategy and application of postsampling weights enhance generalizability. We selected correlates on the basis of previous literature and the behavioral model for vulnerable populations.²⁴ The behavioral model posits that predisposing, enabling, and need characteristics influence health care use.²⁵ The ecological model, which specifies several levels of influence on behavior (e.g., policy, environmental, intrapersonal),²⁶ provided the overall theoretical framework. To our knowledge, we are the first to extensively examine multilevel correlates of farmworker health care use. We sought to identify farmworkers at greatest risk for low health care use and to suggest areas for intervention at all 3 levels of influence so that farmworker service provision can be improved.     

Reinforcement of smoking and drinking: tobacco marketing strategies linked with alcohol in the United States

Objectives. We investigated tobacco companies’ knowledge about concurrent use of tobacco and alcohol, their marketing strategies linking cigarettes with alcohol, and the benefits tobacco companies sought from these marketing activities.Methods. We performed systematic searches on previously secret tobacco industry documents, and we summarized the themes and contexts of relevant search results.Results. Tobacco company research confirmed the association between tobacco use and alcohol use. Tobacco companies explored promotional strategies linking cigarettes and alcohol, such as jointly sponsoring special events with alcohol companies to lower the cost of sponsorships, increase consumer appeal, reinforce brand identity, and generate increased cigarette sales. They also pursued promotions that tied cigarette sales to alcohol purchases, and cigarette promotional events frequently featured alcohol discounts or encouraged alcohol use.Conclusions. Tobacco companies’ numerous marketing strategies linking cigarettes with alcohol may have reinforced the use of both substances. Because using tobacco and alcohol together makes it harder to quit smoking, policies prohibiting tobacco sales and promotion in establishments where alcohol is served and sold might mitigate this effect. Smoking cessation programs should address the effect that alcohol consumption has on tobacco use.Smoking remains the leading preventable cause of premature mortality in the United States, accounting for more than 440 000 deaths annually.¹ Alcohol consumption is the third-leading cause of mortality in the nation.² Each year, approximately 79 000 deaths are attributable to excessive alcohol use.³ The concurrent use of cigarettes and alcohol further increases risks for certain cancers, such as cancer of the mouth, throat, and esophagus.^4,5 In addition, the use of both tobacco and alcohol makes it more difficult to quit either substance.⁶Smoking and drinking are strongly associated behaviors.^7–13 Smokers are more likely to drink alcohol,¹¹ drink more frequently,^8,11 consume a higher quantity of alcohol,^8,11,14 and demonstrate binge drinking (5 or more drinks per episode) than are nonsmokers.^9,11,12 Alcohol drinkers, especially binge drinkers, are also more likely to smoke^7,8,10 and are more likely to smoke half a pack of cigarettes or more per day.¹⁰The association between tobacco use and alcohol use becomes stronger with the heavier use of either substance.^8,15,16 Alcohol consumption increases the desire to smoke,^17,18 and nicotine consumption increases alcohol consumption.¹⁹ Experimental studies have demonstrated that nicotine and alcohol enhance each other''s rewarding effects.^16,18 Alcohol increases the positive subjective effects of smoking,^8,15,16,20 and smoking while using alcohol is more reinforcing than is smoking without concurrent alcohol use.⁸ Smokers smoke more cigarettes while drinking alcohol,^8,15,18 especially during binge-drinking episodes.^8,15 This behavior has also been observed among nondaily smokers^8,15 and light smokers.¹⁷The concurrent use of alcohol and tobacco is common among young adults,^8,10,12,21 including nondaily smokers,^19,22–24 nondependent smokers,⁸ and novice smokers.¹³ Young adult smokers have reported that alcohol increases their enjoyment of and desire for cigarettes^8,25 and that tobacco enhances the effect of alcohol: it “brings on the buzz” or “gave you a double buzz.”^13,23,26 Young adult nondaily smokers described the pairing of alcohol and cigarettes as resembling “milk and cookies” or “peanut butter with jelly.”²⁴ Young adults have also been the focus of aggressive tobacco promotional efforts in places where alcohol is consumed, such as bars and nightclubs.^27,28Consumer products often fall into cohesive groups (sometimes referred to as “Diderot unities”) that may reinforce certain patterns of consumption,²⁹ and these groupings may be influenced by marketing activities. In the case of tobacco and alcohol, these product links may have been further enhanced by cooperation between tobacco and alcohol companies (e.g., cosponsorship) or corporate ownership of both tobacco and alcohol companies (e.g., Philip Morris''s past ownership of Miller Brewing Company).We used tobacco industry documents to explore tobacco companies’ knowledge regarding linked tobacco and alcohol use and the companies’ marketing strategies that linked cigarettes with alcohol. We were interested in 3 basic issues: (1) what tobacco companies knew about the association between drinking and smoking, especially about smokers’ drinking behaviors, (2) how tobacco and alcohol companies developed cross promotions featuring cigarettes and alcohol, and (3) how tobacco companies linked cigarettes with alcohol in their marketing activities and the benefits they expected to gain from those activities.     

Social and physical contexts of schools and neighborhoods: associations with physical activity among young people in New Zealand

Objectives. We sought to determine the association between school- and neighborhood-level characteristics and physical activity among young people.Methods. We collected the data as part of Youth’07, a nationally representative survey of the health and well-being of high school students in New Zealand. In total, 9107 students from 96 schools participated (63% response rate). Students answered questions about their schools (e.g., support for physical activity) and neighborhoods (e.g., community cohesion, disintegration, safety, and recreational facilities). We created school-level measures by aggregating the students’ reports within their schools and we created neighborhood-level measures by aggregating the students’ reports of their neighborhoods to the census area unit of their residential address. We conducted analyses by using cross-classified random-effects models controlling for individual variables, with school and neighborhoods treated as random effects.Results. Schools characterized by high sports team participation and neighborhoods characterized by high social connections were positively associated with student physical activity. We observed few other significant characteristics of school and neighborhood environments.Conclusions. Our findings highlight that opportunity for sports participation and strong social connections in neighborhoods are particularly important for youths’ physical activity.Physical activity patterns among young people are influenced by factors at the individual, school, and community levels. At the individual level, physical activity participation is highest among males and younger adolescents, and socioeconomic differences are less consistently reported.¹ A body of research is emerging that demonstrates the role of schools in student physical activity patterns. Research has demonstrated the social environments and physical environments of schools to be associated with student physical activity behaviors.^2,3 Specifically, social environments of school (e.g., teacher support,⁴ use of physical activity as a reward⁵) and physical environments (e.g., number of recreational features,⁶ accessibility of equipment outside school⁵) are associated with physical activity participation among young people. Yet school-based interventions to increase physical activity among adolescents have demonstrated minimal effectiveness, except when they involve local communities.⁷Thus, there is growing interest and investment in research that aims to determine the influence of community-level factors on population physical activity.^2,8 Neighborhoods can influence the engagement in physical activity by their population through numerous mechanisms including interpersonal relationships (e.g., social supports), social inequalities (e.g., socioeconomic position), and neighborhood characteristics (e.g., cohesion, access to resources, walkability).⁹ The relative importance of the influence of neighborhoods is often debated because adults easily move among neighborhoods for work, residence, and recreation, but young people may be more captive and susceptible to their neighborhood environments.Previous studies examining the relationships between neighborhoods and physical activity have been limited in methodology and measurement. For example, numerous studies have reported the association between perceived availability of recreational facilities and physical activity for young people.^10–13 When these studies are analyzed at the individual level, the major limitation is that young people who are more physically active may perceive more opportunities for physical activity in their environments than do those who are less active. More recently, researchers have improved on the measurement of the physical environment through use of geographic information systems to link objective measures of neighborhood resources.^14,15 Although this approach inherently yields more accurate measures of the neighborhood,¹⁵ it assumes that all young people have equitable access to their neighborhoods and that their perceptions of their environments do not influence how they engage with them. For example, perceived safety of an environment may act as a barrier to physical activity, independent of what the actual reported safety indicators may be.¹⁶ Therefore, reliance on objective measures of the physical environment may overlook significant features of the environment that influence how the population relates to it.Measuring the social contexts of young people and their neighborhoods is somewhat more difficult and cannot easily be achieved with objective measures. Thus, previous studies describing the influence of social contexts in youths’ physical activity have been predominantly operationalized at the level of the student, not the neighborhood. For example, several studies have found associations between peer engagement and parent support and engagement in physical activity with physical activity among young people.^17–19 Fewer studies have used appropriate multilevel statistical techniques to document the relationship between the community social context and youths’ physical activity.² Two studies^20,21 from the Project on Human Development in Chicago Neighborhoods used a multilevel approach and found that neighborhood-level safety and social cohesion are associated with physical activity among young people, but little is known about how generalizable these findings are outside Chicago and with different populations.Our aim, then, was to determine the influence of social and physical features of school and neighborhood environments on youths’ physical activity in a nationally representative sample of secondary school students in New Zealand. We sought to contribute to the growing literature on the topic by using multilevel statistical techniques to examine the associations between both social and physical attributes of schools and neighborhoods and youths’ physical activity in a nationally representative sample.     

Intergenerational relationships between the smoking patterns of a population-representative sample of US mothers and the smoking trajectories of their children

Objectives. We assessed intergenerational transmission of smoking in mother-child dyads.Methods. We identified classes of youth smoking trajectories using mixture latent trajectory analyses with data from the Children and Young Adults of the National Longitudinal Survey of Youth (n = 6349). We regressed class membership on prenatal and postnatal exposure to maternal smoking, including social and behavioral variables, to control for selection.Results. Youth smoking trajectories entailed early-onset persistent smoking, early-onset experimental discontinued smoking, late-onset persistent smoking, and nonsmoking. The likelihood of early onset versus late onset and early onset versus nonsmoking were significantly higher among youths exposed prenatally and postnatally versus either postnatally alone or unexposed. Controlling for selection, the increased likelihood of early onset versus nonsmoking remained significant for each exposure group versus unexposed, as did early onset versus late onset and late onset versus nonsmoking for youths exposed prenatally and postnatally versus unexposed. Experimental smoking was notable among youths whose mothers smoked but quit before the child''s birth.Conclusions. Both physiological and social role-modeling mechanisms of intergenerational transmission are evident. Prioritization of tobacco control for pregnant women, mothers, and youths remains a critical, interrelated objective.Women who smoke during pregnancy are more likely to have offspring who become adolescent smokers.^1–7 Studies link mother''s smoking during pregnancy with youths'' earlier smoking initiation,^3,7–9 greater persistence in regular smoking,^3,7 and stronger nicotine dependency.^6,8,10,11Hypothesized physiological pathways for mother-to-child transmission of smoking are reviewed elsewhere^12–14 and may include inherited susceptibility to addiction alone or in combination with in utero neurodevelopmental exposure and scarring that activates nicotine susceptibility. Furthermore, because few women who smoke during pregnancy quit after delivery^15,16 higher rates of smoking among offspring may reflect role modeling of maternal smoking behavior. Notably, parental smoking is hypothesized to demonstrate pro-smoking norms and solidify pro-smoking attitudes.^17,18Studies considering both smoking during pregnancy and subsequent maternal smoking outcomes have sought to distinguish between these proposed social and physiological transmission pathways.^{1–4,6,7,9,19} Similarly, studies controlling for family sociodemographic factors^{1,2,4,5,7,8,10,11,19,20} or maternal propensity for health or risk taking^1,2,9,10 have sought to further distinguish direct physiological or social transmission from selection. Studies considering children''s cognitive and behavioral outcomes have shown that selection by maternal social and behavioral precursors to smoking during pregnancy strongly biases findings on smoking during pregnancy^21,22; however, it remains unclear whether this is also the case for youth smoking. Some studies^2,3,5,6,19 have observed that smoking during pregnancy operates independently of subsequent maternal smoking. A few have found that smoking during pregnancy is only independently associated in select analyses (e.g., for initiation but not frequency or number of cigarettes^6,9 or only among females^7,20). Several have found that smoking during pregnancy does not operate independently of subsequent maternal smoking behavior,^1,4 and the remaining studies do not address postnatal maternal smoking.^8,9,11We explored whether these inconsistencies in findings supporting social or physiological mechanisms for intergenerational transmission can be accounted for by more comprehensively examining maternal and child smoking behavior. Previous work has established the advantages of statistical models for youth smoking trajectories that capture initiation, experimentation, cessation, or continued use.^23–28 Studies focusing on parental smoking concurrent with youth smoking suggest that postnatal exposures may differentially predispose youths for specific smoking trajectories.^24,26–28 Only 3 known studies have considered whether smoking during pregnancy influences youth smoking progression, and these have shown greater likelihood of early regular use^3,11 and telescoping to dependence.⁸ However, limitations of sample selectivity and measurement and modeling of maternal and youth smoking outcomes restrict the generalizability and scope of these findings.²⁹ To specifically address these limitations and more comprehensively assess hypothesized intergenerational transmission pathways, we used US population–representative data, latent variable techniques, and a rich set of data on maternal and youth smoking and social and behavioral selection factors. We characterized trajectories of youth smoking from adolescence through young adulthood and considered exposure to various maternal smoking patterns from prebirth to the child''s early adolescence.     

Health Among Caregivers of Children With Health Problems: Findings From a Canadian Population-Based Study

Objectives. We used population-based data to evaluate whether caring for a child with health problems had implications for caregiver health after we controlled for relevant covariates.Methods. We used data on 9401 children and their caregivers from a population-based Canadian study. We performed analyses to compare 3633 healthy children with 2485 children with health problems. Caregiver health outcomes included chronic conditions, activity limitations, self-reported general health, depressive symptoms, social support, family functioning, and marital satisfaction. Covariates included family (single-parent status, number of children, income adequacy), caregiver (gender, age, education, smoking status, biological relationship to child), and child (age, gender) characteristics.Results. Logistic regression showed that caregivers of children with health problems had more than twice the odds of reporting chronic conditions, activity limitations, and elevated depressive symptoms, and had greater odds of reporting poorer general health than did caregivers of healthy children.Conclusions. Caregivers of children with health problems had substantially greater odds of health problems than did caregivers of healthy children. The findings are consistent with the movement toward family-centered services recognizing the link between caregivers'' health and health of the children for whom they care.Caring for a child with health problems can entail greater than average time demands,^1,2 medical costs,^3,4 employment constraints,^5,6 and childcare challenges.^6–8 These demands may affect the health of caregivers, a notion supported by a variety of small-scale observational studies that have shown increased levels of stress, distress, emotional problems, and depression among caregivers of children with health problems.^1,2,5,9–12Whether these problems are caused by the additional demands of caring for children with health problems or by confounding variables is difficult to answer definitively. The literature reports the identification of a variety of factors purported to be associated with caregiver health, including contextual factors such as socioeconomic status^13–17; child factors such as level of disability,^{1,11,13,18–21} presence of behavior problems,^22–25 and overall child adjustment²⁶; and caregiver-related characteristics such as coping strategies^11,22,27 and support from friends and family.^15,17,28,29 In general, this work has been based on small clinic-based samples^9,30 or specific child populations (e.g., cerebral palsy,^5,25 attention-deficit/hyperactivity disorder^31,32), and typically has been hampered by limited generalizability and a lack of careful, multivariate analysis. Furthermore, most studies have focused on caregivers'' psychological health,^1,2,5,9–12 although physical health effects may also exist among caregivers.^5,19,25,33One of the few studies to involve large-scale, population-based data compared the health of 468 caregivers of children with cerebral palsy to the health of a population-based sample of Canadian parents.⁵ The study showed that caregivers of children with cerebral palsy had poorer health on a variety of physical and psychological health measures. Furthermore, the data were consistent with a stress process model,^5,25 which proposes that additional stresses associated with caring for a child with cerebral palsy directly contribute to poorer caregiver health. However, these findings were based on a specific subpopulation of caregivers and univariate comparisons that could not control for potentially important confounders such as variation in caregiver education, income, and other demographic factors.We used population-based data to test the hypothesis that the health of caregivers of children with health problems would be significantly poorer than that of caregivers of healthy children, even after we controlled for relevant covariates. Our approach of using large-scale, population-based data representing a broad spectrum of childhood health problems³⁴ makes 4 key contributions to the current literature. First, our use of population-based data rather than small-scale, clinic-based studies yielded results that are potentially generalizable to a wide group of caregivers caring for children with health problems. Second, our examination of children with and without health problems allowed us to examine caregiver health effects across a wide variety of caregiving situations. Third, consideration of physical health outcomes (in addition to more regularly studied psychological outcomes) increased our knowledge of the breadth of caregiver health issues. Finally, controlling for relevant covariates allowed us to rule out a number of alternative explanations for caregiver health effects.     

The association between perceived discrimination and obesity in a population-based multiracial and multiethnic adult sample

Objectives. We examined whether perceived chronic discrimination was related to excess body fat accumulation in a random, multiethnic, population-based sample of US adults.Methods. We used multivariate multinomial logistic regression and logistic regression analyses to examine the relationship between interpersonal experiences of perceived chronic discrimination and body mass index and high-risk waist circumference.Results. Consistent with other studies, our analyses showed that perceived unfair treatment was associated with increased abdominal obesity. Compared with Irish, Jewish, Polish, and Italian Whites who did not experience perceived chronic discrimination, Irish, Jewish, Polish, and Italian Whites who perceived chronic discrimination were 2 to 6 times more likely to have a high-risk waist circumference. No significant relationship between perceived discrimination and the obesity measures was found among the other Whites, Blacks, or Hispanics.Conclusions. These findings are not completely unsupported. White ethnic groups including Polish, Italians, Jews, and Irish have historically been discriminated against in the United States, and other recent research suggests that they experience higher levels of perceived discrimination than do other Whites and that these experiences adversely affect their health.It is estimated that 2 of every 3 adults in the United States are overweight or obese.^1,2 Obesity is a major risk factor for chronic health conditions, such as type 2 diabetes, coronary heart disease, hypertension, stroke, some forms of cancer, and osteoarthritis.³ Although it is widely accepted that high-fat diets and physical inactivity are preventable risk factors,⁴ obesity continues to increase.^1,2,5There is a growing interest in the relationship between psychosocial risk factors and excess body fat accumulation.^6–16 In particular, some evidence suggests that psychosocial stressors may play a role in disease progression in general and in excess body fat in particular.^7,8,17 The key factors underlying physiological reactions to psychosocial stress have not been completely elucidated, but McEwen and Seeman¹⁷ and others^7,18,19 posit that the continued adaptation of the physiological system to external challenges alters the normal physiological stress reaction pathways and that these changes are related to adverse health outcomes.^8,17,18,20 For example, in examining the association between psychosocial stress and excess body fat accumulation, Björntorp and others have suggested that psychosocial stress is linked to obesity, especially in the abdominal area.^7,8Perceived discrimination, as a psychosocial stressor, is now receiving increased attention in the empirical health literature.^21–24 Such studies suggest perceived discrimination is inversely related to poor mental and physical health outcomes and risk factors, including hypertension,^24,25 depressive symptoms,^26–28 smoking,^29–31 alcohol drinking,^32,33 low birthweight,^34,35 and cardiovascular outcomes.^36–38Internalized racism, the acceptance of negative stereotypes by the stigmatized group,³⁹ has also been recognized as a race-related psychosocial risk factor.⁴⁰ Recent studies have also suggested that race-related beliefs and experiences including perceived discrimination might be potentially related to excess body fat accumulation. Three of these studies^9,13,41 showed that internalized racism was associated with an increased likelihood of overweight or abdominal obesity among Black Caribbean women in Dominica⁴¹ and Barbados¹³ and adolescent girls in Barbados.⁹ These researchers posit that individuals with relatively high levels of internalized racism have adopted a defeatist mindset, which is believed to be related to the physiological pathway associated with excess body fat accumulation. However, Vines et al.¹⁶ found that perceived racism was associated with lower waist-to-hip ratios among Black women in the United States. Although the assessment of race-related risk factors varied across these studies, the findings suggest that the salience of race-related beliefs and experiences may be related to excess body fat accumulation.Collectively, the results of these studies are limited. First, because they examined the relationship between race-related beliefs and experiences and excess body fat only among women, we do not know if this relationship is generalizable to men.^13,16,41 Second, these studies only examined this relationship among Blacks, even though perceived unfair treatment because of race/ethnicity has been shown to be adversely related to the health of multiple racial/ethnic population groups in the United States^42–49 and internationally.^27,50–55 Third, none of the studies have examined the relationship between excess body fat accumulation and perceived nonracial/nonethnic experiences of interpersonal discrimination. Some evidence suggests that the generic perception of unfair treatment or bias is adversely related to health, regardless of whether it is attributed to race, ethnicity, or some other reason.^45,55,56 Fourth, none of these studies included other measures of stress. We do not know if the association between race-related risk factors and obesity is independent of other traditional indicators of stress.Using a multiethnic, population-based sample of adults, we examined the association of perceived discrimination and obesity independent of other known risk factors for obesity, including stressful major life events. Additionally, because reports of perceived racial/ethnic discrimination and non-racial/ethnic discrimination vary by racial/ethnic groups^24,45,46,57 and because Whites tend to have less excess body fat than do Blacks and Hispanics,^1,3 we examined the relationships between perceived discrimination and excess body fat accumulation among Hispanics, non-Hispanic Whites, and non-Hispanic Blacks.     

Promoters and Barriers to Fruit, Vegetable, and Fast-Food Consumption Among Urban, Low-Income African Americans��A Qualitative Approach

To identify promoters of and barriers to fruit, vegetable, and fast-food consumption, we interviewed low-income African Americans in Philadelphia. Salient promoters and barriers were distinct from each other and differed by food type: taste was a promoter and cost a barrier to all foods; convenience, cravings, and preferences promoted consumption of fast foods; health concerns promoted consumption of fruits and vegetables and avoidance of fast foods. Promoters and barriers differed by gender and age. Strategies for dietary change should consider food type, gender, and age.Diet-related chronic diseases—the leading causes of death in the United States^1,2—disproportionately affect African Americans^3–7 and those having low income.^8–10 Low-income African Americans tend to have diets that promote obesity, morbidity, and premature mortality^3,4,11,12; are low in fruits and vegetables^13–18; and are high in processed and fast foods.^19–23Factors that may encourage disease-promoting diets include individual tastes and preferences, cultural values and heritage, social and economic contexts, and systemic influences like media and marketing.^24–30 Because previous research on dietary patterns among low-income African Americans has largely come from an etic (outsider) perspective, it has potentially overlooked community-relevant insights, missed local understanding, and failed to identify effective sustainable solutions.³¹ Experts have therefore called for greater understanding of an emic (insider) perspective through qualitative methods.³¹ However, past qualitative research on dietary patterns among low-income African Americans has been limited, focusing mostly or exclusively on ethnic considerations,^28,29 workplace issues,¹⁰ women,^32–38 young people,^38,39 or only those with chronic diseases^34,36,39,40 and neglecting potentially important differences by age and gender.^31,41–43To build on prior research, we conducted interviews in a community-recruited sample using the standard anthropological technique of freelisting.^44–46 Our goals were (1) to identify the promoters of and barriers to fruit, vegetable, and fast-food consumption most salient to urban, low-income African Americans and (2) to look for variation by gender and age.     

Neighborhood socioeconomic status and cognitive function in women

Objectives. We examined whether neighborhood socioeconomic status (NSES) is associated with cognitive functioning in older US women and whether this relationship is explained by associations between NSES and vascular, health behavior, and psychosocial factors.Methods. We assessed women aged 65 to 81 years (n = 7479) who were free of dementia and took part in the Women''s Health Initiative Memory Study. Linear mixed models examined the cross-sectional association between an NSES index and cognitive functioning scores. A base model adjusted for age, race/ethnicity, education, income, marital status, and hysterectomy. Three groups of potential confounders were examined in separate models: vascular, health behavior, and psychosocial factors.Results. Living in a neighborhood with a 1-unit higher NSES value was associated with a level of cognitive functioning that was 0.022 standard deviations higher (P = .02). The association was attenuated but still marginally significant (P < .1) after adjustment for confounders and, according to interaction tests, stronger among younger and non-White women.Conclusions. The socioeconomic status of a woman''s neighborhood may influence her cognitive functioning. This relationship is only partially explained by vascular, health behavior, or psychosocial factors. Future research is needed on the longitudinal relationships between NSES, cognitive impairment, and cognitive decline.A growing body of research suggests that the characteristics of neighborhoods in which individuals live may influence their risk of poor self-rated health, cardiovascular disease, and mortality above and beyond individual-level characteristics.^1–15 The proposed mechanisms by which lower quality neighborhoods may affect physical health include increased exposure to chronic stressors and pollutants in the environment; increased access to alcohol and cigarette outlets; barriers to physical activity; reduced social support, networks, and cohesion; and reduced access to high-quality health and social services. Three recent studies have linked lower neighborhood socioeconomic status (NSES) to lower cognitive function in UK adults older than 52 years,¹⁶ US adults older than 70 years living in urban areas,¹⁷ and Mexican Americans older than 65 years living in 5 southwestern states.¹⁸ However, the mechanisms underlying this relationship are not well understood.Extensive epidemiological research has linked NSES to vascular-related conditions,^4,19–22 poor health behaviors,^23–25 and greater psychosocial stress.^26–30 Incidentally, these factors also have well-established linkages with brain health such that individuals who have vascular-related conditions,^31,32 who engage in low levels of physical activity, whose tobacco and alcohol consumption is excessive,^33–35 and who have pronounced symptoms of depression or low social support^36–38 are at increased risk for poor cognitive function. No studies to date have addressed whether these conditions may explain the relationship between NSES and cognitive function.Previous studies indicate that neighborhood environments may influence poor cognitive function above and beyond individual-level demographic characteristics such as age, race/ethnicity, educational attainment, and income.^16,17,39,40 Certain demographic subgroups may be especially vulnerable to the effects of NSES on cognitive function. For example, poor neighborhood environments may have stronger effects on older adults than on younger adults because older adults spend more time in their neighborhoods⁴¹; may have less access to social, financial, or health services; and have accumulated more exposures to stressors or pollutants. Non-White older adults who live in lower socioeconomic status (SES) neighborhoods may face discrimination or other stressors that may confer greater vulnerability to NSES effects on cognitive function.Wight et al.¹⁷ examined individual- and neighborhood-level educational interactions among US adults. However, no US study to date has addressed whether other individual-level demographic factors may buffer or exacerbate the negative effects on cognitive function of living in a lower SES neighborhood using an index consisting of important measures of SES beyond education alone.We examined whether an NSES index was related to cognitive function in a large, geographically and demographically diverse cohort of older US women with rich data on a sensitive measure of global cognitive function and a comprehensive set of clinical, behavioral, and psychosocial confounders. In addition, we assessed whether the relationship between NSES and cognitive function was explained by risk and protective factors for poor cognitive function that have also been linked with NSES and whether certain subgroups were more vulnerable to lower NSES.     

Life-Course Socioeconomic Position and Incidence of Diabetes Mellitus Among Blacks and Whites: The Alameda County Study, 1965�C1999

Objectives. We examined associations between several life-course socioeconomic position (SEP) measures (childhood SEP, education, income, occupation) and diabetes incidence from 1965 to 1999 in a sample of 5422 diabetes-free Black and White participants in the Alameda County Study.Methods. Race-specific Cox proportional hazard models estimated diabetes risk associated with each SEP measure. Demographic confounders (age, gender, marital status) and potential pathway components (physical inactivity, body composition, smoking, alcohol consumption, hypertension, depression, access to health care) were included as covariates.Results. Diabetes incidence was twice as high for Blacks as for Whites. Diabetes risk factors independently increased risk, but effect sizes were greater among Whites. Low childhood SEP elevated risk for both racial groups. Protective effects were suggested for low education and blue-collar occupation among Blacks, but these factors increased risk for Whites. Income was protective for Whites but not Blacks. Covariate adjustment had negligible effects on associations between each SEP measure and diabetes incidence for both racial groups.Conclusions. These findings suggest an important role for life-course SEP measures in determining risk of diabetes, regardless of race and after adjustment for factors that may confound or mediate these associations.Diabetes mellitus is a major cause of morbidity and mortality in the United States.^1,2 Type 2 diabetes disproportionately affects Hispanics, as well as non-Hispanic Black Americans, American Indians/Alaska Natives, and some Asian/Pacific Islander groups. In the United States, members of racial and ethnic minority groups are almost twice as likely to develop or have type 2 diabetes than are non-Hispanic Whites.^2–5 Significant racial and ethnic differences also exist in the rates of diabetes-related preventive services, quality of care, and disease outcomes.^6–10Researchers have attempted to determine why, relative to Whites, members of racial and ethnic minority groups are disproportionately affected by diabetes. For example, compared with White Americans, Black Americans are presumed to have stronger genetic^5,11 or physiological^11–13 susceptibility to diabetes, or greater frequency or intensity of known diabetes risk factors, such as obesity, physical inactivity, and hypertension.^14–17Black Americans also are more likely than are White Americans to occupy lower socioeconomic positions.¹⁸ Low socioeconomic position (SEP) across the life course is known to influence the prevalence^19–24 and incidence^3,19,25–30 of type 2 diabetes. The risk of diabetes also is greater for people who are obese,^3,17,31 physically inactive,^3,32 or have hypertension,^33,34 all of which are conditions more common among people with lower SEP.^16,35–37Several studies have focused on the extent to which socioeconomic factors, body composition (i.e., weight, height, body mass index, and waist circumference), and behaviors explain the excess risk of diabetes attributed to race.^4,12,19,30 For example, 2 separate studies, one with data from the Health and Retirement Study¹⁹ and the other with data from the Atherosclerosis Risk in Communities Study,³⁰ used race to predict diabetes incidence. Attempting to separate the direct and indirect effects of race on diabetes,³⁸ these studies assessed, via statistical adjustment, which socioeconomic measures and diabetes-related risk factors, when adjusted, could account for the excess risk among Black participants relative to White participants.^19,30 Adjustment for education lessened the effect of Black race on diabetes incidence in the Atherosclerosis Risk in Communities Study.³⁰ In the Health and Retirement Study, excess risk attributed to Black race was not explained by early-life socioeconomic disadvantage, but it was reduced after adjustment for education and later-life economic resources.¹⁹ The validity of this analytic approach has been challenged, however, because the socioeconomic measures used were assumed to have the same meaning across all racial/ethnic groups, a questionable assumption³⁸ in the United States, especially in 1965.We sought to explore the predictive effects of several life-course socioeconomic factors on the incidence of diabetes among both Black and White Americans. We examined demographic confounders (age, gender, marital status) and diabetes risk factors (obesity, large waist circumference, physical inactivity, high blood pressure, depression, access to health care) as possible mediators of the observed associations between SEP and incident diabetes (i.e., the development of new cases of diabetes over time).     

Associations Between Recreational Walking and Attractiveness, Size, and Proximity of Neighborhood Open Spaces

Objectives. We examined associations of attractiveness, size, and proximity of multiple neighborhood open spaces (NOSs) with recreational walking.Methods. Adults participating in the Residential Environments (RESIDE) study (n = 1366) in Perth, Australia, reported time spent engaging in recreational walking within their neighborhoods. Park audit data and geographic information systems were used to identify the most attractive, largest, and nearest NOS within a 1.6-km radius from each participant''s residential location. Regression analysis was used to examine attributes (attractiveness, size, and proximity) of these open spaces and their associations with participants’ recreational walking.Results. Shorter distance to attractive open spaces was associated with doing any recreational walking, but adults with larger attractive open spaces within 1.6 km of their home were more likely to walk 150 minutes or more in a week.Conclusions. For adults, the presence of a large, high-quality park within walking distance of one''s home may be more important in promoting sufficient amounts of walking for health benefits than is the presence of an open space within a shorter distance.The impact of the built environment on health and active living is an emerging field of study.¹ In the United States, the 2001 launch of the Robert Wood Johnson Foundation''s Active Living Research program accelerated growth in this field by promoting multidisciplinary research that includes investigators from health, urban planning, transportation, and leisure.² Research in this area addresses the mechanisms through which community design can influence daily physical activity, and how these findings can be used to develop evidence-based policy aimed at creating user-friendly environments for pedestrians and cyclists.³ It has become increasingly important to identify modifiable, high-leverage environmental attributes that can be used in planning, policy, and practice.Neighborhood open spaces (NOSs), typically parks, provide destinations to which people can walk and are ideal settings for leisure-time physical activity.⁴ Adults with better access to neighborhood green spaces have shown enhanced physical health, which in part is mediated through elevated levels of walking.⁵ Promoting walking is a centerpiece of public health strategy for preventing major chronic diseases, because of its popularity and known health benefits.^6,7 NOS is thus an important resource that has the potential to facilitate more active lifestyles. In addition, there is growing evidence that exposure to natural environments is restorative and beneficial to mental health.^5,8 Given the burden of disease associated with physical inactivity and poor mental health,⁹ understanding how to design NOS to attract residents and encourage use is likely to help enhance population health.⁴Associations have been consistently found between physical activity and the presence of destinations, such as shops and services in neighborhoods.^10–12 However, a review of the relationships between attributes of natural or green open spaces and residents’ physical activity found positive associations in only about half of the studies reviewed, suggesting mixed evidence on this topic.¹³ Inconsistencies may be at least partly attributable to the different methods used to capture the green elements of neighborhoods. Measures used to date can be classified into 2 types: focusing on overall neighborhood greenness, and focusing on a particular NOS. An example of the overall measure is perceived neighborhood greenness, such as the self-reported amount of greenery or access to parks and other green spaces, which has been shown to be associated with walking.^5,14 Objectively measured size or density of green spaces within a neighborhood is another overall measure of greenness. Such objective measures have been found to be associated with physical activity in some studies,^15–17 but not in others.^18,19 A study in the United States used a normalized difference vegetation index (NDVI; the amount of green surface identified using satellite images), and found that this overall measure did not predict residents’ walking.¹⁴ An Australian study identified objective overall access to public open spaces using a gravity model, and found that distance to open spaces alone was not associated with walking.²⁰ Other studies have used a measure focusing on a particular NOS. For instance, the presence of a park within walking distance from a participant''s home was found to be unrelated to physical activity levels.^21,22 Several studies have also reported that the distance to the nearest NOS was not associated with physical activity.^23–25 However, 1 study found that shorter distance to a park was conducive to more activity.²⁶ In addition, walking by older people was associated with the quality of a nearby NOS.²⁷These studies suggest that an objective overall measure of NOS, such as the total size of green spaces in a neighborhood or NDVI, may be inadequate because it cannot distinguish open spaces that encourage physical activity from those that are uninviting or inaccessible. Notably, perceived greenness measures that involved the perception of quality have been found to be associated with participants’ physical activity.^5,14 As the aesthetic aspects of neighborhood environments have been shown to be relevant to residents’ physical activity,²⁸ the attractiveness of open spaces may need to be considered when assessing the relationships between such spaces and participation in physical activity. The presence of park features (e.g., walking paths, facilities for physical activity) is also relevant in this context because they were associated with active park use.²⁹ Measures focusing on a particular NOS (typically, the park closest to a person''s place of residence) may be also inadequate for evaluating the impact of overall green spaces on residents’ behavior, because neighborhoods typically have many open spaces that vary in quality and in size. To better understand the contribution of open space to residents’ physical activity levels, there is a need to examine more comprehensive open space attributes such as attractiveness, size, and proximity. Research also needs to investigate multiple open spaces to more accurately assess the impact of open, green spaces in the neighborhood area on physical activity.In our study, we identified 3 types of NOS that adults may typically visit for recreation: the most attractive, the largest, and the nearest. We then examined which of the 3 attributes—attractiveness, size, and distance—of these open spaces were more strongly associated with adult residents’ recreational walking. We also examined whether the number of open spaces in a neighborhood was associated with recreational walking.     

First-Trimester Working Conditions and Birthweight: A Prospective Cohort Study

Objectives. We investigated the relationship between women''s first-trimester working conditions and infant birthweight.Methods. Pregnant women (N = 8266) participating in the Amsterdam Born Children and Their Development study completed a questionnaire gathering information on employment and working conditions. After exclusions, 7135 women remained in our analyses. Low birthweight and delivery of a small-for-gestational-age (SGA) infant were the main outcome measures.Results. After adjustment, a workweek of 32 hours or more (mean birthweight decrease of 43 g) and high job strain (mean birthweight decrease of 72 g) were significantly associated with birthweight. Only high job strain increased the risk of delivering an SGA infant (odds ratio [OR] = 1.5; 95% confidence interval [CI] = 1.1, 2.2). After adjustment, the combination of high job strain and a long workweek resulted in the largest birthweight reduction (150 g) and the highest risk of delivering an SGA infant (OR = 2.0; 95% CI = 1.2, 3.2).Conclusions. High levels of job strain during early pregnancy are associated with reduced birthweight and an increased risk of delivering an SGA infant, particularly if mothers work 32 or more hours per week.Delivery of a low-birthweight or small-for-gestational-age (SGA) infant as a result of fetal growth restriction is one of the principal adverse pregnancy outcomes. In the short term, low birthweight and small size for gestational age are major determinants of infant mortality and morbidity¹ and impaired neonatal development.² In the long term, they increase metabolic and cardiovascular disease risk.^3–5 Prevention of fetal growth restriction is therefore of undisputed clinical and economic importance.Maternal factors, obstetric factors (e.g., placental dynamics), and social factors,⁵ including employment-related factors, can all play a role in fetal growth impairment.^6–24 Although employment in general is associated with enhanced outcomes,^6,20,21 certain working conditions represent potential risk factors for the mother and child. Increased levels of risk resulting from long working hours,^{12,13,17,18,24} high physical workloads,^13–16 prolonged standing,^13,18 and psychosocial job strain^7,9,10,24 have been suggested, but the findings in this area are not unequivocal.^8,11,22,23 So far, 2 reviews have been conducted that focused on physical workload and delivery of an SGA infant. Mozurkewich et al.¹⁶ concluded from their review of 29 studies that physically demanding work is associated with SGA births (pooled odds ratio [OR] = 1.37; 95% confidence interval [CI] = 1.30, 1.44). Bonzini et al.¹⁹ reached the same conclusion in their study. To our knowledge, job strain has not been considered in any published review.Limitations in research designs,^6,8,19–21 variability in definitions and measurement of work-related factors,^6,18–20 and true variability across countries and cultures may account for the inconsistent results observed to date. Another important limitation of occupational hazard research is the focus on third-trimester exposures.^11,13 Experimental data and emerging theory point to the first rather than the second or third trimester as a crucial period for regulating the relevant fetal hormonal set points, in particular the hypothalamic pituitary axis (HPA).^25–27 Stress-dependent dysregulation of the HPA affects birthweight and a child''s subsequent growth and development.^25–31 From this perspective, employment during pregnancy is perhaps the most prevalent potential stress factor, given that few working women quit their jobs early in pregnancy.In an effort to overcome the limitations of previous studies, we explored the association between infant birthweight and employment-related conditions (e.g., hours worked per week, hours standing or walking, physical demands of work, and job strain) in an unselected urban cohort of pregnant women. We hypothesized that after adjustment for all known major cofactors, first-trimester work-related effects on birthweight would exceed the third-trimester effects reported in previous research.     

Maternal Weathering and Risk of Preterm Delivery

Objectives. We compared the association between advancing maternal age and risk of preterm delivery across 4 groups (Black smokers, Black nonsmokers, White smokers, White nonsmokers) and within the context of neighborhood deprivation levels.Methods. We obtained data from linked census and birth records for singletons (n = 182 938) delivered by women aged 20 to 39 years in Philadelphia, Pennsylvania; Baltimore, Maryland; 16 Michigan cities; 3 Maryland counties; and 2 North Carolina counties. Results from area-specific multilevel logistic regression models were combined to obtain pooled estimates of relations between maternal age and risk of preterm delivery. We repeated the models after categorizing women by neighborhood deprivation level (low, medium, and high).Results. Among multiparous women, there was a significant age-related increase in preterm delivery in 3 of the 4 groups. The adjusted odds ratio per 5-year age increase was 1.31 in Black smokers, 1.11 in Black nonsmokers, and 1.16 in White smokers. In each group, the odds ratio increased as neighborhood deprivation increased.Conclusions. These results support the “weathering” hypothesis, suggesting that Black women, women with high-risk behaviors, and women living in high-deprivation neighborhoods may develop “accelerated aging” that increases preterm delivery risk.The elevated risks of infant mortality¹ and long-term disability² associated with preterm birth are well-documented. Studies have repeatedly shown higher preterm delivery rates among Black women in the United States³ and women in lower socioeconomic strata.^4–7 The association between preterm delivery risk and maternal age has also been frequently studied by means of data from vital records^8–12 or epidemiologic studies.^13–17 Overall, these studies suggest a curvilinear relation, with slightly higher preterm delivery risk in adolescents, lower risk in early adulthood, and increasing risk with advancing maternal age. The shape of this curve might be influenced by multiple factors, including age-related differences in maternal behaviors and physiologic and disease states. There is also self-selection in timing of pregnancies, and later-age pregnancies may include a higher proportion of women with a history of infertility or fetal loss.Building on the observations that adverse pregnancy outcomes increase with advancing maternal age, and noting the marked Black–White disparities in these adverse outcomes, Geronimus proposed a “weathering” or “accelerated aging” hypothesis.¹⁸ This hypothesis states that: (1) a decline in health status contributes to poorer reproductive outcomes as women age and (2) social inequalities lead to an earlier and disproportionately greater decline in the health status of Blacks, which results in a widening health differential between Blacks and Whites with advancing age. In support of the weathering hypothesis, Geronimus and others have shown an increase in Black–White disparities with advancing maternal age for outcomes such as neonatal mortality^18,19 and low and very low birth weight (LBW),^18,20–23 but results for preterm delivery have been inconsistent.^9,12,24 There have also been reports of increasing disparities in adverse pregnancy outcomes with advancing age when women are categorized by measures of disadvantage or socioeconomic status.^20,23,25Based on the framework described by Williams,²⁶ there are multiple potential causes in the pathway to accelerated aging among Black and disadvantaged women, such as delays in accessing health care, employment-related adverse health effects, more obstacles to and fewer opportunities for a healthy lifestyle (e.g., exercise and diet), exposure to air pollutants, high-risk coping behaviors (e.g., smoking, alcohol use, and drug use), and excess stress caused by discrimination, violence, financial troubles, housing insecurity, and lack of instrumental social support. Many of these causes are endemic, and perhaps “infectious,” in neighborhoods with high levels of deprivation.²⁷ Among previous studies that have examined effects of neighborhood poverty level on the associations among race, maternal age, and risk of LBW deliveries, results have been mixed,^20,22,23 and no study has assessed preterm delivery as the primary outcome.In our study we linked birth records to census data from a multisite project to compare the association between advancing maternal age and risk of preterm delivery across groups of women categorized by race and reported smoking status during pregnancy. Although smoking is thought to have direct effects on preterm delivery risk, we also considered smoking to be a potential indicator of high-risk coping behaviors and unhealthy lifestyle. We also examined effects of neighborhood deprivation on the age–preterm delivery relation within the different maternal groups as defined by race and smoking status. We hypothesized that the slope of increasing preterm delivery risk with advancing maternal age would be steeper for Black women, smokers, and women living in neighborhoods with high levels of deprivation.