Geographic variation in work injuries: a multilevel analysis of individual-level data and area-level factors within Canada

PurposeThis study sought to examine provincial variation in work injuries and to assess whether contextual factors are associated with geographic variation in work injuries.MethodsIndividual-level data from the 2003 and 2005 Canadian Community Health Survey was obtained for a representative sample of 89,541 Canadians aged 15 to 75 years old who reported working in the past 12 months. A multilevel regression model was conducted to identify geographic variation and contextual factors associated with the likelihood of reporting a medically attended work injury, while adjusting for demographic and work variables.ResultsProvincial differences in work injuries were observed, even after controlling for other risk factors. Workers in western provinces such as Saskatchewan (adjusted odds ratio [AOR], 1.30; 95% confidence interval [CI], 1.09–1.55), Alberta (AOR, 1.31; 95% CI, 1.13–1.51), and British Columbia (AOR, 1.46; 95% CI, 1.26–1.71) had a higher risk of work injuries compared with Ontario workers. Indicators of area-level material and social deprivation were not associated with work injury risk.ConclusionsProvincial differences in work injuries suggest that broader factors acting as determinants of work injuries are operating across workplaces at a provincial level. Future research needs to identify the provincial determinants and whether similar large area–level factors are driving work injuries in other countries.     

Income inequality and health in Ontario: a multilevel analysis

OBJECTIVE: To examine the association of income inequality at the public health unit level with individual health status in Ontario. METHODS: Cross-sectional multilevel study carried out among subjects aged 25 years or older residing in 42 public health units in Ontario. Individual-level data drawn from 30,939 respondents in 1996-97 Ontario Health Survey. Median area income and income inequality (Gini coefficient) calculated from 1996 census. Self-rated health status (SRH) and Health Utilities Index (HUI-3) scores were used as main outcomes. RESULTS: Controlling for individual-level factors including income, respondents living in public health units in the highest tercile of income inequality had odds ratios of 1.20 (95% CI 1.04 - 1.38) for fair/poor self-rated health, and 1.11 (95% CI 1.01 - 1.22) for HUI score below the median, compared with people living in public health units in the lowest tercile. Controlling further for median area income had little effect on the association. CONCLUSION: Income inequality was significantly associated with individual self-reported health status at public health unit level in Ontario, independent of individual income.     

Income distribution and cause-specific mortality

The aim was to identify the age-, sex- and cause-specific prematuremortality rates contributing to the association between lifeexpectancy and income distribution in developed countries. Incomedistribution was calculated for the 13 OECD countries and yearsfor which the Luxembourg Income Study held data. The potentialyears of life lost (1–65 years) by sex and cause, as wellas the age- and sex-specific all-cause mortality rates and standardizedmortality ratios for children 1–19 years were calculatedfrom data supplied by the WHO. On finding evidence suggestingthat reported income distribution is strongly affected by lowresponse rates in some income surveys, we used 2 measures ofincome distribution: that among households where the ‘headof household’ was aged less than 65 years (weighted byresponse rates) and that among households with children (amongwhom response rates are thought to be higher). Partial correlationsand regressions controlling for the year were used to analysethe relationship between mortality and income distribution.Both measures of income distribution showed broadly similarresults. A more egalitarian distribution of income was relatedto lower all-cause mortality rates In both sexes in most agegroups. All 6 major categories of cause of death contributedto this relationship. The causes of premature mortality contributingmost were road accidents, chronic liver disease and cirrhosis,infections, Ischaemic heart disease among women and other Injuriesamong men. Income distribution was associated not only withlarger absolute changes in mortality from these causes, butalso with larger proportionate changes. Suicides and stomachcancer tended to be more common In more egalitarian countries.     

Neighborhood disadvantage,individual-level socioeconomic position and physical function: A cross-sectional multilevel analysis

IntroductionUnderstanding associations between physical function and neighborhood disadvantage may provide insights into which interventions might best contribute to reducing socioeconomic inequalities in health. This study examines associations between neighborhood-disadvantage, individual-level socioeconomic position (SEP) and physical function from a multilevel perspective.MethodsData were obtained from the HABITAT multilevel longitudinal (2007-13) study of middle-aged adults, using data from the fourth wave (2013). This investigation included 6004 residents (age 46–71 years) of 535 neighborhoods in Brisbane, Australia. Physical function was measured using the PF-10 (0–100), with higher scores indicating better function. The data were analyzed using multilevel linear regression and were extended to test for cross-level interactions by including interaction terms for different combinations of SEP (education, occupation, household income) and neighborhood disadvantage on physical function.ResultsResidents of the most disadvantaged neighborhoods reported significantly lower physical function (men: β − 11.36 95% CI − 13.74, − 8.99; women: β − 11.41 95% CI − 13.60, − 9.22). These associations remained after adjustment for individual-level SEP. Individuals with no post-school education, those permanently unable to work, and members of the lowest household income had significantly poorer physical function. Cross-level interactions suggested that the relationship between household income and physical function is different across levels of neighborhood disadvantage for men; and for education and occupation for women.ConclusionLiving in a disadvantaged neighborhood was negatively associated with physical function after adjustment for individual-level SEP. These results may assist in the development of policy-relevant targeted interventions to delay the rate of physical function decline at a community-level.     

Income inequality and health: multilevel analysis of Chilean communities

STUDY OBJECTIVE: The evidence supporting the effect of income inequality on health has been largely observed in societies far more egalitarian than the US. This study examines the cross sectional multilevel associations between income inequality and self rated poor health in Chile; a society more unequal than the US. DESIGN: A multilevel statistical framework of 98 344 people nested within 61 978 households nested within 285 communities nested within 13 regions. SETTING: The 2000 National Socioeconomic Characterization Survey (CASEN) data from Chile. PARTICIPANTS: Adults aged 18 and above. The outcome was a dichotomised self rated health (0 if very good, good or average; 1 if poor, or very poor). Individual level exposures included age, sex, ethnicity, marital status, education, employment status, type of health insurance, and household level exposures include income and residential setting (urban/rural). Community level exposures included the Gini coefficient and median income. Main results: Controlling for individual/household predictors, a significant gradient was observed between income and poor self rated health, with very poor most likely to report poor health (OR: 2.94) followed by poor (OR: 2.77), low (OR: 2.06), middle (OR: 1.73), high (OR: 1.38) as compared with the very high income earners. Controlling for household and community effects of income, a significant effect of community income inequality was observed (OR:1.22). CONCLUSIONS: Household income does not explain any of the between community differences; neither does it account for the effect of community income inequality on self rated health, with more unequal communities associated with a greater probability of reporting poor health.     

Adolescents alcohol-use and economic conditions: a multilevel analysis of data from a period with big economic changes

This paper examines how the unemployment rate is related to adolescent alcohol use and experience of binge drinking during a time period characterized by big societal changes. The paper uses repeated cross-sectional adolescent survey data from a Swedish region, collected in 1988, 1991, 1995, 1998, 2002 and 2005, and merges this with data on local unemployment rates for the same time periods. Individual level frequency of alcohol use as well as experience of binge drinking is connected to local level unemployment rate to estimate the relationship using multilevel modeling. The model includes municipality effects controlling for time-invariant differences between municipalities as well as year fixed effects controlling for municipality-invariant changes over time in alcohol use. The results show that the unemployment rate is negatively associated with adolescents’ alcohol use and the experience of binge drinking. When the unemployment rate increases, more adolescents do not drink at all. Regular drinking (twice per month or more) is, on the other hand, unrelated to the unemployment rate. Examining gender-differences in the relationship, it is shown that the results are driven by behavior in girls, whereas drinking among boys does not show any significant relationship with changes in the unemployment rate.     

Recent increase of neighborhood socioeconomic effects on ischemic heart disease mortality: a multilevel survival analysis of two large Swedish cohorts

Studies have shown that the decrease in ischemic heart disease mortality over the past decades was paralleled by an increase in socioeconomic disparities. Using two large Swedish cohorts defined in 1986 and 1996, the authors examined whether the effect of neighborhood socioeconomic position on ischemic heart disease mortality strengthened over the period and whether the relative contribution of individual and neighborhood socioeconomic effects changed over time. Multilevel survival models adjusted for individual factors indicated that neighborhood socioeconomic effects on ischemic heart disease mortality increased markedly between the two periods (hazard ratios for residing in the most vs. least deprived neighborhoods were 1.60 (95% credible interval: 1.36, 1.89) for the 1986 cohort and 2.54 (95% credible interval: 1.99, 3.21) for the 1996 cohort). Comparing the neighborhood socioeconomic effect with the strongly predictive effect of 15-year individual income indicated that the neighborhood effect was two times weaker than the individual effect in the 1986 cohort (-48%, 95% credible interval: -22%, -68%) but of comparable magnitude in the 1996 cohort (-11%, 95% credible interval: -42%, 29%). This increase in the contribution of neighborhood factors to the socioeconomic gradient in ischemic heart disease urges investigation into the exact mechanisms between the residential context and coronary health.     

Income inequality and mortality: a multilevel prospective study of 521 248 individuals in 50 US states

BACKGROUND: Some of the most consistent evidence in favour of an association between income inequality and health has been among US states. However, in multilevel studies of mortality, only two out of five studies have reported a positive relationship with income inequality after adjustment for the compositional characteristics of the state's inhabitants. In this study, we attempt to clarify these mixed results by analysing the relationship within age-sex groups and by applying a previously unused analytical method to a database that contains more deaths than any multilevel study to date. METHODS: The US National Longitudinal Mortality Study (NLMS) was used to model the relationship between income inequality in US states and mortality using both a novel and previously used methodologies that fall into the general framework of multilevel regression. We adjust age-sex specific models for nine socioeconomic and demographic variables at the individual level and percentage black and region at the state level. RESULTS: The preponderance of evidence from this study suggests that 1990 state-level income inequality is associated with a 40% differential in state level mortality rates (95% CI = 26-56%) for men 25-64 years and a 14% (95% CI = 3-27%) differential for women 25-64 years after adjustment for compositional factors. No such relationship was found for men or women over 65. CONCLUSIONS: The relationship between income inequality and mortality is only robust to adjustment for compositional factors in men and women under 65. This explains why income inequality is not a major driver of mortality trends in the United States because most deaths occur at ages 65 and over. This analysis does suggest, however, the certain causes of death that occur primarily in the population under 65 may be associated with income inequality. Comparison of analytical techniques also suggests coefficients for income inequality in previous multilevel mortality studies may be biased, but further research is needed to provide a definitive answer.     

Comparing Swedish hospital discharge records with death certificates: implications for mortality statistics

BACKGROUND: The quality of mortality statistics is of crucial importance to epidemiological research. Traditional editing techniques used by statistical offices capture only obvious errors in death certification. In this study we match Swedish hospital discharge data to death certificates and discuss the implications for mortality statistics. METHODS: Swedish death certificates for 1995 were linked to the national hospital discharge register. The resulting database comprised 69 818 individuals (75% of all deaths), 39 872 (43%) of whom died in hospital. The diagnostic statements were compared at Basic Tabulation List level. RESULTS: The last main diagnosis and the underlying cause of death agreed in 46% of cases. Agreement decreased rapidly after discharge. For hospital deaths, the main diagnosis was reported on 83% of the certificates, but only on 46% of certificates for non-hospital deaths. Malignant neoplasms and other dramatic conditions showed the best agreement and were often reported as underlying causes. Conditions that might follow from some other disease were often reported as contributory causes, while symptomatic and some chronic conditions were often omitted. In 13% of cases, an ill-defined main condition was replaced by a more specific cause of death. CONCLUSIONS: There is no apparent reason to question the death certificate if the main diagnosis and underlying cause agree, or if the main diagnosis is a probable complication of the stated underlying cause. However, cases in which the main diagnosis cannot be considered a complication of the reported underlying cause should be investigated, and assessments made of the feasibility and cost-effectiveness of routinely linking hospital records to death certificates.     

Assessment of the magnitude of geographical variations and socioeconomic contextual effects on ischaemic heart disease mortality: a multilevel survival analysis of a large Swedish cohort

BACKGROUND: In a public health perspective, it is of interest to assess the magnitude of geographical variations in ischaemic heart disease (IHD) mortality and quantify the strength of contextual effects on IHD. OBJECTIVE: To investigate whether area effects vary according to the individual and contextual characteristics of the population, socioeconomic contextual influences were assessed in different age groups and within territories of differing population densities. DESIGN: Multilevel survival analysis of a 28-year longitudinal database. PARTICIPANTS: 341 048 residents of the Scania region in Sweden, reaching age 50-79 years in 1996, followed up over 7 years. RESULTS: After adjustment for several individual socioeconomic indicators over the adult age, Cox multilevel models indicated geographical variations in IHD mortality and socioeconomic contextual effects on the mortality risk. However, the magnitude of geographical variations and strength of contextual effects were modified by the age of individuals and the population density of their residential area: socioeconomic contextual effects were much stronger among non-elderly than among elderly adults, and much larger within urban territories than within rural ones. As a consequence, among non-elderly residents of urban territories, the socioeconomic contextual effect was almost as large as the effect of individual 20-year cumulated income. CONCLUSIONS: Non-elderly residents of deprived urban neighbourhoods constitute a major target for both contextual epidemiology of coronary disease and public health interventions aimed at reducing the detrimental effects of the social environment on IHD.     

Arsenic exposure and mortality: a case-referent study from a Swedish copper smelter

An increased mortality from lung cancer, cardiovascular disease, haematolymphatic malignancy and cirrhosis of the liver has been reported among smelter workers and others exposed to arsenic. This study uses the case-referent (case-control) technique and is concerned with workers in a copper smelter in a complex work environment, characterised by the presence of trivalent arsenic in combination with sulphur dioxide and copper, and also with other agents. Lung cancer mortality was found to be increased about five-fold and cardiovascular disease about two-fold, showing a dose-response relationship to arsenic exposure. Mortality from malignant blood disease (leukaemia and myeloma) and cirrhosis of the liver was also slightly increased. This mortality pattern among the smelter workers is consistent with earlier reports. An increased mortality from cardiovascular disease in this type of industry is of particular interest as it has been reported only once before.     

Unintentional injury in Ireland: a comparison of mortality and morbidity data

BACKGROUND: The aim of this study was to examine the relationship between mortality and hospital admission data for the leading causes of unintentional injury in Ireland. METHODS: Mortality data were obtained from the Central Statistics Office for the years 1980-1996. Information on hospital admissions was obtained from the Hospital In-Patient Enquiry system for the years 1993-1997. RESULTS: Motor vehicle traffic accidents were the leading cause of unintentional injury death. Falls were the most common cause of unintentional injury hospital admission. Drowning and suffocation had high ratios of deaths to admissions, 2:1 and 1:3, respectively. The ratio of deaths to admissions was 1:39 for all unintentional injuries. CONCLUSION: Neither mortality data nor admissions data alone give an adequate guide to the impact of injuries, but together the two provide a reasonable basis on which to establish policy.     

Business cycles and mortality: results from Swedish microdata

We assess the relationship between business cycles and mortality risk using a large individual level data set on over 40,000 individuals in Sweden who were followed for 10-16 years (leading to over 500,000 person-year observations). We test the effect of six alternative business cycle indicators on the mortality risk: the unemployment rate, the notification rate, the deviation from the GDP trend, the GDP change, the industry capacity utilization, and the industry confidence indicator. For men we find a significant countercyclical relationship between the business cycle and the mortality risk for four of the indicators and a non-significant effect for the other two indicators. For women we cannot reject the null hypothesis of no effect for any of the business cycle indicators.     

Alcohol abuse and economic conditions: evidence from repeated cross-sections of individual-level data

This study presents novel evidence on the relationship between macroeconomic conditions and patterns of alcohol consumption. Prior research has suggested that alcohol abuse varies procyclically, implying that income effects dominate any drinking patterns related to the opportunity cost of time or the psychological stress of recessions. However, those inferences have been based either on aggregate measures of consumption volume or possibly confounded cross-sectional identification strategies. This study examines these issues by evaluating detailed consumption data from the more than 700 000 respondents who participated in the Center for Disease Control and Prevention's Behavioral Risk Factor Surveillance System (BRFSS) surveys over the 1984-1995 period. The results provide robust evidence that the prevalence of binge drinking is strongly countercyclical. Furthermore, even among those who remain employed, binge drinking increased substantially during economic downturns. This combination of results suggests that recession-induced increases in the prevalence of binge drinking do not simply reflect an increased availability of leisure and may instead reflect the influence of economic stress.     

Predicting small area health-related behaviour: a comparison of multilevel synthetic estimation and local survey data

A recent paper in Social Science and Medicine (Twigg et al. 50 (2000) 1109) outlined an approach to the estimation of prevalences of small-area health-related behaviour using multilevel models. This paper compares results from the application of the multilevel approach with those derived using the more traditional strategy of the local 'lifestyle' survey. Estimations of smoking prevalence and high alcohol consumption are examined and critical assessments made of both estimation approaches. It is concluded that the alternative method is more suited towards the prediction of smoking rates as opposed to unsafe alcohol consumption.     

Arsenic exposure and mortality: a case-referent study from a Swedish copper smelter.

An increased mortality from lung cancer, cardiovascular disease, haematolymphatic malignancy and cirrhosis of the liver has been reported among smelter workers and others exposed to arsenic. This study uses the case-referent (case-control) technique and is concerned with workers in a copper smelter in a complex work environment, characterised by the presence of trivalent arsenic in combination with sulphur dioxide and copper, and also with other agents. Lung cancer mortality was found to be increased about five-fold and cardiovascular disease about two-fold, showing a dose-response relationship to arsenic exposure. Mortality from malignant blood disease (leukaemia and myeloma) and cirrhosis of the liver was also slightly increased. This mortality pattern among the smelter workers is consistent with earlier reports. An increased mortality from cardiovascular disease in this type of industry is of particular interest as it has been reported only once before.     

Early mortality experience in a large military cohort and a comparison of mortality data sources

Background  

Complete and accurate ascertainment of mortality is critically important in any longitudinal study. Tracking of mortality is particularly essential among US military members because of unique occupational exposures (e.g., worldwide deployments as well as combat experiences). Our study objectives were to describe the early mortality experience of Panel 1 of the Millennium Cohort, consisting of participants in a 21-year prospective study of US military service members, and to assess data sources used to ascertain mortality.