Why does lung function predict mortality? Results from the Whitehall II Cohort Study

The authors examined the extent to which socioeconomic position, behavior-related factors, cardiovascular risk factors, inflammatory markers, and chronic diseases explain the association between poor lung function and mortality in 4,817 participants (68.9% men) from the Whitehall II Study aged 60.8 years (standard deviation, 5.9), on average. Forced expiratory volume in 1 second (FEV(1)) was used to measure lung function in 2002-2004. A total of 139 participants died during a mean follow-up period of 6.4 years (standard deviation, 0.8). In a model adjusted for age and sex, being in the lowest tertile of FEV(1)/height(2) was associated with a 1.92-fold (95% confidence interval: 1.35, 2.73) increased risk of mortality compared with being in the top 2 tertiles. Once age, sex, and smoking history were taken into account, the most important explanatory factors for this association were inflammatory markers (21.3% reduction in the FEV(1)/height(2)-mortality association), coronary heart disease, stroke, and diabetes (11.7% reduction), and alcohol consumption, diet, physical activity, and body mass index (9.8% reduction). The contribution of socioeconomic position and cardiovascular risk factors was small (≤ 3.5% reduction). Taken together, these factors explained 32.5% of the association. Multiple pathways link lung function to mortality; these results show inflammatory markers to be particularly important.     

Sexual Function among Women in Midlife: Findings from the Nurses’ Health Study II

BackgroundWomen's sexual well-being is an important determinant of overall health and quality of life across the life course. Yet the factors associated with women's levels of sexual activity and sexual function in midlife are little understood. This study sought to assess the prevalence of recent sexual activity and sexual dysfunction symptoms among middle-aged women and evaluate the associations of partner status, menopause, and health status factors with sexual dysfunction.MethodsParticipants of this cross-sectional study were 68,131 women who responded to the 2013 Nurses’ Health Study II observational cohort questionnaire when they were age 48–68 years. Sexual activity and dysfunction symptoms were assessed with the Female Sexual Function Index. Age-adjusted multivariable regression models estimated risk ratios for the association of health-related factors with past month sexual dysfunction symptoms among women who were sexually active over the past month, overall and stratified by partner status.ResultsOf middle-aged women participants, 73% were sexually active (n = 49,701) and 50% of sexually active women reported symptoms of sexual dysfunction. Symptoms of sexual dysfunction were less common among unpartnered than partnered women (42% vs. 51%; p < .0001). A positive association between menopause and sexual dysfunction was greater for unpartnered women (risk ratio, 2.37, 2.99; p < .001) than partnered women (risk ratio, 1.89, 2.00; p < .001).ConclusionsDifficulty with sexual function is common among women in midlife, but less so than previously estimated. Regular monitoring of women's sexual function could enable clinicians to offer women timely, supportive interventions tailored by partner status and menopausal status.     

Why does length of stay vary for orthopaedic surgery?

This study examines the variation in length of stay in orthopaedic surgery in Grampian in 1988. It highlights the extent of variability across clinicians for patients with the same condition. The results indicate the importance of patient's age, type of admission and Diagnosis-Related Group. The inclusion of variables to identify the consultant in charge significantly improves the explanatory power of the model for all of the seven conditions investigated.     

Variations in health behaviours among inner city 12‐year‐olds from four ethnic groups

Objectives. To describe factors that contribute to variations in health‐related behaviours and attitudes among inner city 12‐year‐olds. To see if there was an identifiable patterning by ethnic group.

Design. Semi‐structured interviews with a stratified sample of 12‐year‐old students and their parents from four ethnic groups, attending state secondary schools in two inner London boroughs.

Results. Bangladeshi young people were significantly more likely to receive school meals. There was no variation in reported snacking between the groups. Girls and Bangladeshi students were less likely to report exercising outside school (33% of Bangladeshi boys reported not exercising outside school compared to 5% of boys from all other groups). Bangladeshi boys and their parents were more likely to report that bullying or worries about racial violence prevented them from going out after school. White young people were more likely to report experimenting with and the regular use of cigarettes and alcohol. Use of alcohol and cigarettes was also associated with gender, religion and strength of religious observance. White parents were the least likely to report restricting their child's social activities as a way of influencing behaviour and expressed more concerns about their child's potential for health‐damaging behaviour than parents in all other groups.

Conclusion. This study shows that ethnicity alone is insufficient and inadequate in explaining variations in health behaviours among inner city teenagers. A complex mix of personal, cultural and social factors including ethnicity shape the behaviours and attitudes of these young people.     

Why are the low birthweight rates in Brazil higher in richer than in poorer municipalities? Exploring the epidemiological paradox of low birthweight

Socio-economic disadvantage is usually associated with low birthweight (LBW). However, it has been shown that Mexican Americans, despite being economically less advantaged, present LBW rates that are similar to or lower than those found among white women in the US. This fact has been called 'the epidemiological paradox of low birthweight'. Natality data from Brazil revealed the existence of a similar paradox: LBW rates are higher in more developed than in less developed regions within the country. In this study, data from two population-based cohort studies carried out in the nineties, including 2439 births in Sao Luis, a poor city in north-eastern Brazil, and 2839 births in Ribeirao Preto, a socio-economically well-off city in south-eastern Brazil, were used to explore this paradox. The method proposed by Wilcox and Russell and a graphic analysis of the frequency distribution of birthweight according to gestational age were used to provide indirect information about possible gestational age misclassification. Contrary to expectations, the LBW rate was higher in Ribeirao Preto than in Sao Luis (10.7 vs. 7.6%, P <0.001), while preterm birth (PTB) rate (12.7 vs. 12.1%, P=0.520) and percentage of small-for-gestational-age (SGA) infants (12.5 vs. 13.5%, P=0.290) were similar for the two cities. However, SGA rate among preterm infants was higher in Ribeirao Preto (16.4 vs. 9.8%, P=0.014). A bimodal distribution of birthweight was observed for children with less than 32 weeks in Sao Luis. As estimated by the Wilcox and Russell method, the residual distribution was greater in Ribeirao Preto than in Sao Luis (3.4 vs. 2.4%). Part of the LBW paradox observed for the two cities was due to the higher PTB rate and higher number of preterm SGA infants in Ribeirao Preto. Factors such as greater medical intervention in preterm newborns close to the end of pregnancy in more developed municipalities, artefacts in the determination of gestational age, and the under-registration of livebirths and registration of livebirths as stillbirths in less developed municipalities may explain why LBW rates in Brazil are higher in richer than in poorer municipalities.     

Dietary fibre and cardiovascular disease mortality in the UK Women’s Cohort Study

Dietary fibre has been associated with improvements in key risk factors for cardiovascular disease (CVD). Prior research has focussed more on CVD development in men and our aim was therefore to explore the association between dietary fibre intake and CVD mortality using data from the United Kingdom Women’s Cohort Study (UKWCS). Dietary fibre intake from 31,036 women was calculated both as non-starch polysaccharide (NSP) and using the Association of Official Analytical Chemist (AOAC) method from food-frequency questionnaires. Participants were free from history of CVD at baseline and mean age at recruitment was 51.8 years (standard deviation 9.2). Mortality records for participants were linked from national registry data and 258 fatal CVD cases [130 stroke, 128 coronary heart disease (CHD)] were observed over an average follow-up period of 14.3 years. Total dietary fibre (NSP/AOAC) and fibre from different food sources were not associated with fatal CHD, stroke or CVD risk in the full sample. For every 6 g/day increase in NSP, the hazard ratio (HR) was 0.91 (95 % confidence interval (CI) 0.76–1.08) or for every 11 g/day increase in fibre assessed as AOAC, the HR was 0.92 (95 % CI 0.80–1.05). Sensitivity analyses suggest a possible protective association for cereal sources of fibre on fatal stroke risk in overweight women, HR 0.80 (95 % CI 0.65–0.93) p < 0.01. In the UKWCS, a sample of health-conscious women, greater dietary fibre intake may confer no additional cardiovascular benefit, in terms of mortality, but may contribute to lower fatal stroke risk in some subgroups such as overweight women.     

Is ethnic density associated with health in a context of social disadvantage? Findings from the Born in Bradford cohort

Objectives. In this study we aimed to test the associations between area-level ethnic density and health for Pakistani and White British residents of Bradford, England.

Design. The sample consisted of 8610 mothers and infant taking part in the Born in Bradford cohort. Ethnic density was measured as the percentage of Pakistani, White British or South Asian residents living in a Lower Super Output Area. Health outcomes included birth weight, preterm birth and smoking during pregnancy. Associations between ethnic density and health were tested in multilevel regression models, adjusted for individual covariates and area deprivation.

Results. In the Pakistani sample, higher own ethnic density was associated with lower birth weight (β = ?0.82, 95% CI: ?1.63, ?0.02), and higher South Asian density was associated with a lower probability of smoking during pregnancy (OR = 0.99, 95% CI: 0.98, 1.00). Pakistani women in areas with 50?70% South Asian residents were less likely to smoke than those living in areas with less than 10% South Asian residents (OR = 0.39, 95% CI: 0.16, 0.97). In the White British sample, neither birth weight nor preterm birth was associated with own ethnic density. The probability of smoking during pregnancy was lower in areas with 10?29.99% compared to <10% South Asian density (OR = 0.79, 95% CI: 0.64, 0.98).

Conclusion. In this sample, ethnic density was associated with lower odds of smoking during pregnancy but not with higher birth weight or lower odds of preterm birth. Possibly, high levels of social disadvantage inhibit positive effects of ethnic density on health.     

The heavier the better? Birthweight and perinatal mortality in different ethnic groups

BACKGROUND: Mother's ethnicity is associated with her baby's birthweight and risk of perinatal mortality. Given the close relation between birthweight and perinatal mortality, we explored whether ethnic differences in birthweight explain ethnic differences in perinatal mortality. METHODS: Data on all births to mothers born in Norway (808 658), Pakistan (6854), Vietnam (3283) and North Africa (1461) from 1980 to 1995 were obtained from the Medical Birth Registry of Norway. The associations between birthweight and perinatal mortality among ethnic groups were analysed using univariate and multivariate methods. RESULTS: Mean birthweights were low for Vietnamese and Pakistani mothers (3202 g, 3244 g) and high for Norwegian and North African mothers (3530 g, 3559 g). Mean birthweights were largely unrelated to perinatal mortality, which was lowest for Vietnamese (8.2/1000, 95% CI: 5.1-11.3) and highest for Pakistanis (14.9/1000, 95% CI: 12.0-17.7). Intermediate perinatal mortality rates were found among Norwegians (9.5/1000, 95% CI: 9.3-9.7) and North Africans (9.6/1000, 95% CI: 4.6-14.6). Further comparison of weight-specific mortality rates between the two largest ethnic groups showed the low birthweight paradox, where among low-weight births, perinatal mortality was lower among Pakistani than among Norwegian babies. However, adjustment to a relative birthweight scale (units of standard deviations from population-specific mean value) revealed higher rates of weight-specific mortality among Pakistanis across the entire range of birthweights. Multivariate adjustment for relative birthweight and other factors did not change these results. CONCLUSIONS: Differences in perinatal mortality between the ethnic groups were not explained by differences in mean birthweight. Paradoxical differences in birthweight-specific mortality rates could be resolved by adjustment to a relative scale.     

Why does dieting predict weight gain in adolescents? Findings from project EAT-II: a 5-year longitudinal study

OBJECTIVE: Dieting has been found to predict weight gain in adolescents, but reasons for this association remain unclear. This study aimed to explore potential mechanisms by which dieting predicts weight gain over time in adolescents. DESIGN: Population-based, 5-year longitudinal study. PARTICIPANTS: Adolescents (n=2,516) from diverse ethnic and socioeconomic backgrounds who completed Project EAT (Eating Among Teens) surveys in 1999 (Time 1) and 2004 (Time 2). MAIN OUTCOME MEASURE: Body mass index (BMI) change over 5 years. STATISTICAL ANALYSIS: Multiple regressions were used to examine associations between Time 1 dieting and Time 2 binge eating, breakfast consumption, fruit and vegetable intake, and physical activity. Associations were then examined between these behaviors and BMI change. Finally, to test for mediating effects, associations between dieting and BMI change were examined with and without the inclusion of these behaviors, and regression coefficients were compared. RESULTS: In female adolescents, dieting predicted increased binge eating (P<0.001) and decreased breakfast consumption (P=0.030). In male adolescents, dieting predicted increased binge eating (P<0.001), decreased physical activity (P=0.006), and a trend toward decreased breakfast consumption (P=0.064). These behaviors were also associated with increases in BMI. The association between dieting and BMI increase was weakened, but still remained significant, after binge eating, breakfast consumption, fruit/vegetable intake, and physical activity were included in the model being tested. Thus, the longitudinal association between dieting and BMI increase was partially mediated by these behaviors. CONCLUSIONS: In part, dieting may lead to weight gain via the long-term adoption of behavioral patterns that are counterproductive to weight management.     

Women’s knowledge about heart disease: Differences among ethnic and cultural groups in the Israeli Women’s Health in Midlife Study

Abstract

The current investigation aimed to assess levels of knowledge about risk factors for heart disease among midlife Israeli women, and to evaluate the relationship of knowledge to personal risk factors and vulnerability to heart disease. Face-to-face interviews with women aged 45–64 years were conducted during 2004–2006 within three population groups: long-term Jewish residents (LTR), immigrants from the former Soviet Union, and Arab women. The survey instrument included six knowledge statements relating to: the risk after menopause, family history, elevated cholesterol level, diabetes, obesity, and warning signs of a heart attack. The findings showed wide disparities in knowledge by educational level and between immigrants and LTR, after taking into account personal risk factors and education. Personal risk factors were not significantly related to the knowledge items, except for personal history of cardiovascular disease, which was associated with knowledge about “warning signs of a heart attack” and “family history.” Women who perceived themselves as more vulnerable to heart disease were more likely to identify several risk factors correctly. These findings stress the need to increase knowledge about heart disease, especially among less educated and minority women, and to emphasize the risk of patients’ personal status by health providers.     

Health consumer groups in the UK: a new social movement?

This paper argues that a health consumer movement has developed in the United Kingdom over the last decade. Drawing on two empirical studies of groups that promote and/or represent the interests of patients, users and carers, it argues that groups formed by people with personal experience of a condition are now more widespread. Feelings of pain and loss can lead to the identification of others in a similar position, and to the formation of groups and action in the political sphere. Research shows that groups share a common discourse and follow similar participative practices, and there is extensive networking. Informal and formal alliances have formed to pursue joint action and indicate a wider health consumer movement. As governments have also increased the opportunities for participation, this has the potential for patients and carers to shape services in ways more responsive to their needs.     

A multi-group path analysis of the relationship between perceived racial discrimination and self-rated stress: how does it vary across racial/ethnic groups?

Objective: The objective of this study was to answer three questions: (1) Is perceived discrimination adversely related to self-rated stress via the social capital and health care system distrust pathways? (2) Does the relationship between perceived discrimination and self-rated stress vary across race/ethnicity groups? and (3) Do the two pathways differ by one’s race/ethnicity background?

Design: Using the Philadelphia Health Management Corporation’s Southeastern Pennsylvania Household Survey, we classified 9831 respondents into 4 race/ethnicity groups: non-Hispanic White (n?=?6621), non-Hispanic Black (n?=?2359), Hispanic (n?=?505), and non-Hispanic other races (n?=?346). Structural equation modeling was employed to simultaneously estimate five sets of equations, including the confirmatory factor analysis for both social capital and health care distrust and both direct and indirect effects from perceived discrimination to self-rated stress.

Results: The key findings drawn from the analysis include the following: (1) in general, people who experienced racial discrimination have higher distrust and weaker social capital than those without perceived discrimination and both distrust and social capital are ultimately related to self-rated stress. (2) The direct relationship between perceived discrimination and self-rated stress is found for all race/ethnicity groups (except non-Hispanic other races) and it does not vary across groups. (3) The two pathways can be applied to non-Hispanic White and Black, but for Hispanic and non-Hispanic other races, we found little evidence for the social capital pathway.

Conclusions: For non-Hispanic White, non-Hispanic Black, and Hispanic, perceived discrimination is negatively related to self-rated stress. This finding highlights the importance of reducing interpersonal discriminatory behavior even for non-Hispanic White. The health care system distrust pathway can be used to address the racial health disparity in stress as it holds true for all four race/ethnicity groups. On the other hand, the social capital pathway seems to better help non-Hispanic White and Black to mediate the adverse effect of perceived discrimination on stress.     

Does vitamin d deficiency account for ethnic differences in tuberculosis seasonality in the UK?

Objectives. Notifications of tuberculosis in England and Wales are reported to peak in the summer season. The purpose of this study was to confirm that finding and to determine to what extent patients of Indian Subcontinent (ISC) ethnic origin contributed to the seasonality. The clinical presentation of the disease is presumed to occur some months following reactivation of the endogenous latent focus of tuberculosis infection. There arises the possibility of vitamin D deficiency producing immunological inadequacy at the end of winter and beginning of spring.

Patients and methods. Monthly (or 4‐weekly) aggregated data over 7 years were collected from the three countries of mainland Britain, England, Wales, Scotland and from the city of Birmingham in England. The notifications from Birmingham were divided into those of ISC ethnic origin and ‘whites’. The presence or absence of seasonality was determined by fitting a sinusoidal curve by the technique called ‘cosinor analysis’. In this method amplitude gives a measure of the extent of the seasonal variation.

Results. The summer peak of clinical diagnosis was confirmed in the UK series from England, Wales and Scotland. In England and Wales without Scotland a larger seasonal variation was present. Scotland, with a lower proportion of population of ISC ethnic origin, was examined separately and the results in Scotland alone failed to confirm seasonality. In the data from Birmingham, seasonality was confirmed with a greater amplitude, particularly in those over 60 years of age. The finding was influenced by those of ISC ethnic origin, seasonality not being present in the ‘white’ population.

Conclusion. The results from Birmingham are very striking, but there were almost three times as many patients in the ISC ethnic group as in indigenous ‘white’ patients. A series with larger numbers of ‘white’ patients would be necessary to confirm the absence of seasonality in the ‘white’ population. The discussion reviews the evidence that vitamin D may have an important hormonal role in immunological defence in the prevention of tuberculosis.     

Why have physical activity levels declined among Chinese adults? Findings from the 1991–2006 China health and nutrition surveys

Between 1991 and 2006, average weekly physical activity among adults in China fell by 32%. This paper discusses why total and occupational physical activity levels have fallen, and models the association between the rapid decline and various dimensions of exogenous community urbanization. We hypothesize that a) physical activity levels are negatively associated with urbanization; b) urbanization domains that affect job functions and opportunities will contribute most to changes in physical activity levels; and c) these urbanization domains will be more strongly associated for men than for women because home activities account for a larger proportion of physical activity for women. To test these hypotheses, we used longitudinal data from individuals aged 18–55 in the 1991–2006 China Health and Nutrition Surveys. We find that physical activity declines were strongly associated with greater availability of higher educational institutions, housing infrastructure, sanitation improvements and the economic wellbeing of the community in which people function. These urbanization factors predict more than four-fifths of the decline in occupational physical activity over the 1991–2006 period for men and nearly two-thirds of the decline for women. They are also associated with 57% of the decline in total physical activity for men and 40% of the decline for women. Intervention strategies to promote physical activity in the workplace, at home, for transit and via exercise should be considered a major health priority in China.