Are geographic regions with high income inequality associated with risk of abdominal weight gain?

Heterogeneity in disparities by income in cardiovascular risk factors across 209 US metropolitan areas

Objective

The United States has a lower life expectancy and wider income inequality than its similarly developed counterparts, and disparities continue to widen. The objective of our study is to examine the heterogeneity of disparities by income in cardiovascular disease (CVD) risk factors among U.S. metropolitan areas.

Methods

Data was obtained from the Behavioral Risk Factor Surveillance System for 2012-2019. We used self-reported data for respondent characteristics and for CVD risk factors/prevalence, and on metropolitan-level demographic and socioeconomic characteristics. We computed the relative index of inequality (RII) for each outcome using a multilevel Poisson model, sequentially adjusted for age, sex, and race/ethnicity with a random slope for income. We also included interactions between income and the metropolitan-level variables.

Results

Our sample included 1.4 million participants from 209 metropolitan areas. All CVD risk factors and CVD demonstrated income-related disparities. There were no clear regional patterns for risk factors, though seven of the top 10 large metropolitan areas with the widest disparities in CVD prevalence were in the South. Improved socioeconomic conditions were associated with wider disparities in the five risk factors, and contextual variables explained almost half of the variability in income disparities in smoking, sedentarism, and obesity, even after adjusting for age, sex, and race/ethnicity.

Conclusions

This study found that CVD risk factors and prevalence in U.S. metropolitan areas have heterogeneous income disparities, especially in advantaged metropolitan areas. Further studies with improved data collection may shed more light into potential drivers of income-based disparities in cardiovascular risk.

Economic inequality in malnutrition: a global systematic review and meta-analysis

OBJECTIVE

To describe the evidence on global and regional economic inequality in malnutrition, and the associations between economic inequality and malnutrition.

METHODS

We conducted a systematic review and meta-analysis. Between 1 November 2020 and 22 January 2021, we searched Medline, Embase, Global Health, Eldis, Web of Science and EBSCO Discovery Service. We contacted 39 experts and tracked citations. We included any study reporting a concentration index (CIX) relating economic status and nutritional status and any multilevel study reporting an association between economic inequality and nutritional status. Nutritional status was measured as stunting, wasting, anaemia, or overweight in children (<5 years), or underweight, overweight or obesity, or anaemia in adults (15-49 years). We had no study date or language restriction. Quality was assessed using the Appraisal Tool for Cross-Sectional Studies (AXIS tool). We mapped estimates and pooled them using multilevel random-effects meta-analyses.

RESULTS

From 6185 results, 91 studies provided 426 CIX (>2.9 million people) and 47 associations (~3.9 million people). Stunting (CIX -0.15 (95% CI -0.19 to -0.11)) and wasting (-0.03 (95% CI -0.05 to -0.02)) are concentrated among poor households. Adult overweight and obesity is concentrated in wealthier households (0.08 (95% CI -0.00 to 0.17)), particularly in South Asia (0.26 (95% CI 0.19 to 0.34)), but not in Europe and Central Asia (-0.02 (95% CI -0.08 to 0.05)) or North America (-0.04 (95% CI -0.10 to 0.03)). We found no association between 0.1 increase in Gini coefficient and adult underweight (OR 1.03 (95% CI 0.94 to 1.12)) or overweight and obesity (0.92 (95% CI 0.80 to 1.05)).

CONCLUSIONS

There is good evidence that the prevalence of malnutrition varies by levels of absolute economic status. Undernutrition is concentrated in poor households, whereas concentration of overweight and obesity by economic status depends on region, and we lack information on economic inequalities in anaemia and child overweight. In contrast, links between malnutrition and relative economic status are less clear and should not be assumed; robust evidence on causal pathways is needed.

PROSPERO REGISTRATION NUMBER

CRD42020201572.

Biomarkers, disability and health care demand

Using longitudinal data from a representative UK panel, we focus on a group of apparently healthy individuals with no history of disability or major chronic health condition at baseline. A latent variable structural equation model is used to analyse the predictive role of latent baseline biological health, indicated by a rich set of biomarkers, and other personal characteristics, in determining the individual's disability state and health service utilisation five years later. We find that baseline biological health affects future health service utilisation very strongly, via progression to functional disability channel. We also find systematic income gradients in future disability risks, with those of higher income experiencing a lower progress to disability. Our model reveals that observed pro-rich inequity in health care utilisation, is driven by the fact that higher-income people tend to make greater use of health care treatment, for any given biological health and disability status; this is despite the lower average need for treatment shown by the negative association of income with both baseline ill biological health and disability progression risk. Factor loadings for latent baseline health show that a broader set of blood-based biomarkers, rather than the current focus mainly on blood pressure, cholesterol and adiposity, may need to be considered for public health screening programs.

State-level income inequality and the odds for meeting fruit and vegetable recommendations among US adults

Background

Previous research indicates that income inequality is associated with risk for mortality, self-rated health status, chronic conditions, and health behavior, such as physical activity. However, little is known about the relationship between income inequality and dietary intake, which is a major risk factor for common chronic diseases including heart disease, stroke, diabetes, and certain types of cancers. The objective of this study is to determine the association between US state income inequality and fruit and vegetable consumption among adults.

Methods

Cross-sectional data on 270,612 U.S. adults from the U.S. 2013 Behavioral Risk Factor Surveillance System was used. Fruit and vegetable consumption was assessed from the six-item fruit and vegetable frequency questionnaire, which is part of the Behavioral Risk Factor Surveillance System. Multilevel modeling was used to determine whether US state-level income inequality (measured by the z-transformation of the Gini coefficient) was associated with fruit and vegetable consumption adjusting for individual-level and state-level covariates.

Results

In comparison to men, women were more likely to consume fruits and vegetables ≥5 times daily, fruits ≥2 times daily, vegetables ≥3 times of daily, and less likely to consume fruit juice daily. Among both men and women, a standard deviation increase in Gini coefficient was associated with an increase in consuming fruit juice daily (OR = 1.07, 95% CI = 1.03, 1.11). However, among women, a standard deviation increase in Gini coefficient was associated with a decreased likelihood in meeting daily recommended levels of both fruits and vegetables (OR = 0.93; 0.87–0.99), fruits only (OR = 0.95; 95% CI, 0.92–0.99) and vegetables only (OR = 0.92; 95% CI, 0.89–0.96).

Conclusions

This study is one of the first to show the relationship between income inequality and fruit and vegetable consumption among U.S. adults empirically. Women’s health is more likely to be detrimentally affected when living in a state with higher income inequality.

Delayed Effects of Obese and Overweight Population Conditions on All-Cause Adult Mortality Rate in the USA

Currently, there are few studies separating the linkage of pathological obese and overweight body mass indices (BMIs) to the all-cause mortality rate in adults. Consequently, this paper, using annual Behavioral Risk Factor Surveillance System data of the 50 US states and the District of Columbia, estimates empirical regression models linking the US adult overweight (25 ≤ BMI < 30) and obesity (BMI ≥ 30) rates to the all-cause deaths rate. The biochemistry of multi-period cumulative adiposity (saturated fatty acid) from unexpended caloric intakes (net energy storage) provides the natural theoretical foundation for tracing unhealthy BMI to all-cause mortality. Cross-sectional and panel data regression models are separately estimated for the delayed effects of obese and overweight BMIs on the all-cause mortality rate. Controlling for the independent effects of economic, socio-demographic, and other factors on the all-cause mortality rate, our findings confirm that the estimated panel data models are more appropriate. The panel data regression results reveal that the obesity-mortality link strengthens significantly after multiple years in the condition. The faster mortality response to obesity detected here is conjectured to arise from the significantly more obese. Compared with past studies postulating a static (rather than delayed) effects, the statistically significant lagged effects of adult population BMI pathology in this study are novel and insightful. And, as expected, these lagged effects are more severe in the obese than overweight population segment. Public health policy implications of this social science study findings agree with those of the clinical sciences literature advocating timely lifestyle modification interventions (e.g., smoking cessation) to slow premature mortality linked with unhealthy BMIs.

Tract- and county-level income inequality and individual risk of obesity in the United States

OBJECTIVES

We tested three alternative hypotheses regarding the relationship between income inequality and individual risk of obesity at two geographical scales: U.S. Census tract and county.

METHODS

Income inequality was measured by Gini coefficients, created from the 2000 U.S. Census. Obesity was clinically measured in the 2003-2008 National Health and Nutrition Examination Survey (NHANES). The individual measures and area measures were geo-linked to estimate three sets of multi-level models: tract only, county only, and tract and county simultaneously. Gender was tested as a moderator.

RESULTS

At both the tract and county levels, higher income inequality was associated with lower individual risk of obesity. The size of the coefficient was larger for county-level Gini than for tract-level Gini; and controlling income inequality at one level did not reduce the impact of income inequality at the other level. Gender was not a significant moderator for the obesity-income inequality association.

CONCLUSIONS

Higher tract and county income inequality was associated with lower individual risk of obesity, indicating that at least at the tract and county levels and in the context of cross-sectional data, the public health goal of reducing the rate of obesity is in line with anti-poverty policies of addressing poverty through mixed-income development where neighborhood income inequality is likely higher than homogeneous neighborhoods.

Neighborhood disparities in access to healthy foods and their effects on environmental justice

Environmental justice is concerned with an equitable distribution of environmental burdens. These burdens comprise immediate health hazards as well as subtle inequities, such as limited access to healthy foods. We reviewed the literature on neighborhood disparities in access to fast-food outlets and convenience stores. Low-income neighborhoods offered greater access to food sources that promote unhealthy eating. The distribution of fast-food outlets and convenience stores differed by the racial/ethnic characteristics of the neighborhood. Further research is needed to address the limitations of current studies, identify effective policy actions to achieve environmental justice, and evaluate intervention strategies to promote lifelong healthy eating habits, optimum health, and vibrant communities.

Food insecurity, social capital and perceived personal disparity in a predominantly rural region of Texas: an individual-level analysis

Few studies have addressed the association of food insecurity with place of residence and perceptions of collective social functioning such as perceived social capital and perceived personal disparity. This study assessed the association between food insecurity and measures of perceived personal disparity and perceived social capital in a region of Central Texas, USA comprised of one urban and six rural counties. Food insecurity, perceived social capital, perceived personal disparity, and sociodemographic control measures were derived from the 2006 Brazos Valley Community Health Assessment on an analytic sample of 1803 adult participants (74% response rate). Robust multinomial regression models examined associations between food insecurity and perceived personal disparity, perceived social capital, education, age, residence in a poor or low-income household, minority group membership, and rural residence. A model was estimated for food insecurity (n = 1803, p < 0.0001). Residents with low social capital, higher levels of perceived personal disparity, rural residence, residence in a low-income or poor household, minority group membership, and lower levels of educational attainment were more likely to experience food insecurity. Rural residence (p = 0.021) was significant only for the comparison between those who never, and those who often experienced food insecurity, and findings for the stratified rural and urban samples were roughly equivalent to the combined sample. Individual level measures of collective social functioning are important correlates of food insecurity. In this study, both perceived personal disparity and perceived social capital play an important role, regardless of rural or urban residence.

Disparities in obesity temporal trends of Israeli adolescents by ethnic origin

OBJECTIVE

To analyze the temporal trends of obesity over time among male adolescents of different ethnic origins.

METHODS

Population-based national data of subjects presenting at recruitment centers for medical examinations as part of screening for military draft. Subjects were 17-year-old Jewish males (n=1 140 937) born in the years 1950-1986. Data on body mass index (BMI) were measured (without clothing and shoes) by physicians. We calculated the prevalence of obesity (BMI 29.4 or higher) for each year by ethnic origin group. A Multinomial logistic regression model was used to estimate the effects of ethnic origin and other risk factors on the likelihood of obesity.

RESULTS

Over time, obesity rates have risen among all ethnic groups of adolescents. Multinomial regression analysis showed a lower likelihood of obesity among those of Asia-Africa origin as compared with other groups. However, obesity rates have increased more significantly over time among this ethnic group compared with the other groups.

CONCLUSION

A significant finding of this study is the disparities in temporal trends in the likelihood of obesity over time. Among adolescents of Asia-Africa origin the likelihood of obesity increased more steeply over time compared with other groups of adolescents. Health services in Israel should thus consider Asia-African origin as a distinct risk factor and target interventions to prevent future obesity among these adolescents.

Symposium on ‘Intervention policies for deprived households’ Policy initiatives to address low-income households' nutritional needs in the UK

Members of low-income households in the UK are more likely to have patterns of food and nutrient intakes that are less inclined to lead to good health outcomes in the short and long term. Health inequalities, including the likelihood of child and adulthood obesity, have long been documented in the UK and show little sign of improving so far, despite 10 years of attention from a government that has committed itself to addressing them. Following the Acheson Inquiry into Inequalities in Health (1998) in England a number of initiatives to tackle inequalities in food and diet were established, both nationally and within the devolved nations of Scotland, Wales and Northern Ireland. Nevertheless, until recently, there has been no overall strategic policy addressing the food and nutritional needs of low-income households. The present paper reviews how the problems have been constructed and understood and how they have been addressed, briefly drawing on recent evaluations of food and nutrition policies in Scotland and Wales. The contemporary challenge is to frame cross-cutting policy initiatives that move beyond simple targeting and local actions, encompass a life-course approach and recognise both the diversity of households that fall into ‘low-income’ categories and the need for ‘upstream’ intervention.

Population-based prevention of obesity: the need for comprehensive promotion of healthful eating, physical activity, and energy balance: a scientific statement from American Heart Association Council on Epidemiology and Prevention, Interdisciplinary Committee for Prevention (formerly the expert panel on population and prevention science)

Obesity is a major influence on the development and course of cardiovascular diseases and affects physical and social functioning and quality of life. The importance of effective interventions to reduce obesity and related health risks has increased in recent decades because the number of adults and children who are obese has reached epidemic proportions. To prevent the development of overweight and obesity throughout the life course, population-based strategies that improve social and physical environmental contexts for healthful eating and physical activity are essential. Population-based approaches to obesity prevention are complementary to clinical preventive strategies and also to treatment programs for those who are already obese. This American Heart Association scientific statement aims: 1) to raise awareness of the importance of undertaking population-based initiatives specifically geared to the prevention of excess weight gain in adults and children; 2) to describe considerations for undertaking obesity prevention overall and in key risk subgroups; 3) to differentiate environmental and policy approaches to obesity prevention from those used in clinical prevention and obesity treatment; 4) to identify potential targets of environmental and policy change using an ecological model that includes multiple layers of influences on eating and physical activity across multiple societal sectors; and 5) to highlight the spectrum of potentially relevant interventions and the nature of evidence needed to inform population-based approaches. The evidence-based experience for population-wide approaches to obesity prevention is highlighted.

Fat nation: deciphering the distinctive geographies of obesity in England

Much attention is focused on obesity by both the media and by public health. As a health risk, obesity is recognised as a contributing factor to numerous health problems. Recent evidence points to a growth in levels of obesity in many countries and particular attention is usually given to rising levels of obesity among younger people. England is no exception to these generalisations with recent studies revealing a clear geography to what has been termed an 'obesity epidemic.' This paper examines the complexities inherent in the geography of adult obesity in England. Existing knowledge about the sub-national geography of obesity is examined and assessed. Multilevel synthetic estimation is then used to construct an age-sex-ethnicity disaggregated geography of obesity. These differing geographies are compared and contrasted with pre-existing findings and explored at multiple scales. A complex picture of the geography of obesity in England is revealed.

Obesity, physical activity, and the urban environment: public health research needs

Persistent trends in overweight and obesity have resulted in a rapid research effort focused on built environment, physical activity, and overweight. Much of the focus of this research has been on the design and form of suburbs. It suggests that several features of the suburban built environment such as low densities, poor street connectivity and the lack of sidewalks are associated with decreased physical activity and an increased risk of being overweight. But compared to suburban residents, inner city populations have higher rates of obesity and inactivity despite living in neighborhoods that are dense, have excellent street connectivity and who's streets are almost universally lined with sidewalks. We suggest that the reasons for this apparent paradox are rooted in the complex interaction of land use, infrastructure and social factors affecting inner city populations. Sometimes seemingly similar features are the result of very different processes, necessitating different policy responses to meet these challenges. For example, in suburbs, lower densities can result from government decision making that leads to restrictive zoning and land use issues. In the inner city, densities may be lowered because of abandonment and disinvestment. In the suburbs, changes in land use regulations could result in a healthier built environment. In inner cities, increasing densities will depend on reversing economic trends and investment decisions that have systematically resulted in distressed housing, abandoned buildings and vacant lots. These varying issues need to be further studied in the context of the totality of urban environments, incorporating what has been learned from other disciplines, such as economics and sociology, as well as highlighting some of the more successful inner city policy interventions, which may provide examples for communities working to improve their health. Certain disparities among urban and suburban populations in obesity and overweight, physical activity and research focus have emerged that are timely to address. Comparable research on the relationship of built environment and health is needed for urban, especially inner city, neighborhoods.

Educational, economic and dietary determinants of obesity in Portuguese adults: a cross-sectional study

In industrialized countries, studies have shown that lower socioeconomic status is generally associated with higher rates of obesity. Furthermore, poorer eating habits with insufficient intake of low energy-dense and micronutrient rich foods may increase the risk of obesity. The aim of this study was to evaluate the importance of educational, economic and dietary factors in determining obesity risk in a representative sample of the Portuguese general adult population. Study design was cross-sectional in a representative sample of Portuguese adults (20,977 women and 18,663 men). Participants were distributed in categories according to years of education (< or =4, 5-9, 10-12, and >12), income (< or =314 euros, 315-547 euros, 548-815 euros, and >815 euros), and dietary intake (vegetable soup, vegetable, fruit, bread and starchy foods). Logistic regression models were fitted to estimate the magnitude of the association between obesity and education/income, and food groups, adjusting for confounders. In women and men, the odds favouring obesity decreased with increasing education (p-value for trend <0.001) being the odds ratios, respectively, 0.19 (0.14-0.27), and 0.40 (0.30-0.54) for those having >12 years of education compared to those with < or =4 years vegetable; soup consumption also decreased the risk of obesity in both genders (odds ratios were very similar in women and men, being respectively, 0.86 and 0.89). The odds favouring obesity in women also decreased with consumption of fruit and starchy foods, being the odds ratios, respectively, 0.77 (0.64-0.92), and 0.65 (0.55-0.78). In conclusion, educational attainment and vegetable intake decreased significantly the risk of obesity in Portuguese adults from both genders; fruits and starchy foods consumption also decreased the risk of obesity in women.

US state- and county-level social capital in relation to obesity and physical inactivity: a multilevel, multivariable analysis

Although social capital has been linked to a variety of health outcomes, its association with obesity has yet to be elucidated. This study explored the relations between social capital measured at the US state and county levels and individual obesity and leisure-time physical inactivity. Individual-level data were drawn from the 2001 Behavioral Risk Factor Surveillance System survey, while data from other surveys and administrative sources were used to construct contextual measures. Two state-level social capital scales were derived from 10 indicators and two county-level scales from five indicators. In 2-level analyses of over 167,000 adults nested within 48 states plus the District of Columbia, residence in a state above the median on one or both state social capital scales (vs. neither scale) was associated with lower relative odds of obesity and physical inactivity, controlling for individual-level covariables and state-level estimates of mean household income, the Gini coefficient, and the percentage of Black residents. In 3-level analyses, the adjusted odds ratio (OR) for physical inactivity associated with residence in a county above the median on one or both county social capital scales was significantly below 1, while the association with obesity was not significant. Significantly weaker inverse ORs for the relations between state- and county-level social capital and obesity were observed among American Indians/Alaska Natives compared to Whites. Meanwhile, little support was found for mediation by social capital of the associations of urban sprawl and income inequality with obesity or physical inactivity. Overall, this study provides some evidence for the promotion of social capital as a potential strategy for addressing the burgeoning obesity epidemic.

Income inequality and population health: A review and explanation of the evidence

Whether or not the scale of a society's income inequality is a determinant of population health is still regarded as a controversial issue. We decided to review the evidence and see if we could find a consistent interpretation of both the positive and negative findings. We identified 168 analyses in 155 papers reporting research findings on the association between income distribution and population health, and classified them according to how far their findings supported the hypothesis that greater income differences are associated with lower standards of population health. Analyses in which all adjusted associations between greater income equality and higher standards of population health were statistically significant and positive were classified as "wholly supportive"; if none were significant and positive they were classified as "unsupportive"; and if some but not all were significant and supportive they were classified as "partially supportive". Of those classified as either wholly supportive or unsupportive, a large majority (70 per cent) suggest that health is less good in societies where income differences are bigger. There were substantial differences in the proportion of supportive findings according to whether inequality was measured in large or small areas. We suggest that the studies of income inequality are more supportive in large areas because in that context income inequality serves as a measure of the scale of social stratification, or how hierarchical a society is. We suggest three explanations for the unsupportive findings reported by a minority of studies. First, many studies measured inequality in areas too small to reflect the scale of social class differences in a society; second, a number of studies controlled for factors which, rather than being genuine confounders, are likely either to mediate between class and health or to be other reflections of the scale of social stratification; and third, the international relationship was temporarily lost (in all but the youngest age groups) during the decade from the mid-1980s when income differences were widening particularly rapidly in a number of countries. We finish by discussing possible objections to our interpretation of the findings.

Wider income gaps, wider waistbands? An ecological study of obesity and income inequality

OBJECTIVES

To see if obesity, deaths from diabetes, and daily calorie intake are associated with income inequality among developed countries.

DESIGN

Ecological study of 21 developed countries.Countries: Countries were eligible for inclusion if they were among the top 50 countries with the highest gross national income per capita by purchasing power parity in 2002, had a population over 3 million, and had available data on income inequality and outcome measures.

MAIN OUTCOME MEASURES

Percentage of obese (body mass index >30) adult men and women, diabetes mortality rates, and calorie consumption per capita per day.

RESULTS

Adjusting for gross national per capita income, income inequality was positively correlated with the percentage of obese men (r = 0.48, p = 0.03), the percentage of obese women (r = 0.62, p = 0.003), diabetes mortality rates per 1 million people (r = 0.46, p = 0.04), and average calories per capita per day (r = 0.50, p = 0.02). Correlations were stronger if analyses were weighted for population size. The effect of income inequality on female obesity was independent of average calorie intake.

CONCLUSIONS

Obesity, diabetes mortality, and calorie consumption were associated with income inequality in developed countries. Increased nutritional problems may be a consequence of the psychosocial impact of living in a more hierarchical society.

Primary care, social inequalities and all-cause, heart disease and cancer mortality in US counties: a comparison between urban and non-urban areas

OBJECTIVE

The objective of this study was to test whether the association between primary care and income inequality on all-cause, heart disease and cancer mortality at county level differs in urban (Metropolitan Statistical Area-MSA) compared with non-urban (non-MSA) areas.

STUDY DESIGN

The study consisted of a cross-sectional analysis of county-level data stratified by MSA and non-MSA areas in 1990. Dependent variables included age and sex-standardized (per 100,000) all-cause, heart disease and cancer mortality. Independent variables included primary care resources, income inequality, education levels, unemployment, racial/ethnic composition and income levels.

METHODS

One-way analysis of variance and multivariate ordinary least squares regression were employed for each health outcome.

RESULTS

Among non-MSA counties, those in the highest income inequality category experienced 11% higher all-cause mortality, 9% higher heart disease mortality, and 9% higher cancer mortality than counties in the lowest income inequality quartile, while controlling for other health determinants. Non-MSA counties with higher primary care experienced 2% lower all-cause mortality, 4% lower heart disease mortality, and 3% lower cancer mortality than non-MSA counties with lower primary care. MSA counties with median levels of income inequality experienced approximately 6% higher all-cause mortality, 7% higher heart disease mortality, and 7% higher cancer mortality than counties in the lowest income inequality quartile. MSA counties with low primary care (less than 75th percentile) had significantly lower levels of all-cause, heart disease and cancer mortality than those counties with high primary care.

CONCLUSIONS

In non-MSA counties, increasing primary physician supply could be one way to address the health needs of rural populations. In MSA counties, the association between primary care and health outcomes appears to be more complex and is likely to require intervention that focuses on multiple fronts.

Suicidal ideation and associated factors among community-dwelling elders in Taiwan

The purpose of the present study was to explore the suicidal ideation of community-dwelling elderly and the factors associated with their intention to commit suicide. Using a multilevel stratified sampling strategy, 1000 elderly subjects were recruited (aged 65-74 years old) in Taiwan during the year 2001. The degree of depression and its correlates were assessed. Suicidal ideation was measured by asking respondents if they had had any suicidal thoughts in the previous week. In all, 16.7% of respondents reported suicidal ideation within the past week; its occurrence was related to sex, religious belief, employment status, marital status, average family monthly income, physical health status, depressive symptoms, and community activity participation. Further multivariate logistic regression revealed that, aside from depressive symptoms and a lower level of education, no community participation in the past 6 months was significantly associated with the appearance of suicidal ideation. The prevalence of suicidal ideation among the elderly in Taiwan is higher than in Western countries. Participation in social activities is negatively associated with elderly suicidal ideation. The dimension of social participation deserves further exploration and should be considered in community mental health promotion interventions for elderly people.

Primary care, social inequalities, and all-cause, heart disease, and cancer mortality in US counties, 1990

OBJECTIVES

We tested the association between the availability of primary care and income inequality on several categories of mortality in US counties.

METHODS

We used cross-sectional analysis of data from counties (n=3081) in 1990, including analysis of variance and multivariate ordinary least squares regression. Independent variables included primary care resources, income inequality, and sociodemographics.

RESULTS

Counties with higher availability of primary care resources experienced between 2% and 3% lower mortality than counties with less primary care. Counties with high income inequality experienced between 11% and 13% higher mortality than counties with less inequality.

CONCLUSIONS

Primary care resources may partially moderate the effects of income inequality on health outcomes at the county level.

Income inequality and weight status in US metropolitan areas

Prior empirical studies have demonstrated an association between income inequality and general health endpoints such as mortality and self-rated health, and findings have been taken as support for the hypothesis that inequality is detrimental to individual health. Unhealthy weight statuses may function as an intermediary link between inequality and more general heath endpoints. Using individual-level data from the 1996-98 Behavioral Risk Factor Surveillance System, we examine the relationship between individual weight status and income inequality in US metropolitan areas. Income inequality is calculated with data from the 1990 US Census 5% Public Use Microsample. In analyses stratified by race-sex groups, we do not find a positive association between income inequality and weight outcomes such as body mass index, the odds of being overweight, and the odds of being obese. Among white women, however, we do find a statistically significant inverse association between inequality and each of these weight outcomes, despite adjustments for individual-level covariates, metropolitan-level covariates, and census region. We also find that greater inequality is associated with higher odds for trying to lose weight among white women, even adjusting for current weight status. Although our findings are suggestive of a contextual effect of metropolitan area income inequality, we do not find an increased risk for unhealthy weight outcomes, adding to recent debates surrounding this topic.

A multilevel analysis of race, community disadvantage, and body mass index among adults in the US

This study examined the contributions of both individual socioeconomic status (SES) and community disadvantage in explaining the higher body mass index (BMI) of black adults in the US. Data from a national survey of adults (1986 American's Changing Lives Study) were combined with tract-level community data from the 1980 census. Results of multilevel regression analyses showed that black women had an age-adjusted BMI score three points higher than non-black women. Individual SES (income, education, assets) was negatively associated with BMI in women, but it only reduced the association between race and BMI from 2.99 to 2.50. Adding community socioeconomic disadvantage index further reduced the race coefficient slightly from 2.50 to 2.21. Nevertheless, living in communities with higher socioeconomic disadvantage was associated with higher BMI net of age, race, individual SES, smoking, physical activity, stress, and social support. Community income inequality (Gini) had an independent positive association with BMI, but did not substantially reduce racial differences among women. Community percent black was not associated with BMI. Results for men demonstrated no statistically significant racial differences in BMI, and no association between BMI and either individual SES or community disadvantage. Although individual SES and community socioeconomic disadvantage each partly explained the higher average BMI among black women, clear racial disparities persisted. Moreover, race, individual SES, community socioeconomic disadvantage, and individual health behaviors were each independent predictors of BMI among women. Unexplained within- and between-community variance in BMI remained among both women and men, with most unexplained variation due to within-community variance. Because our evidence for women suggests that the determinants of obesity are multiple and multilevel, attempts to address this growing social problem will similarly require a multi-faceted and multilevel approach.

Primary care, infant mortality, and low birth weight in the states of the USA

STUDY OBJECTIVE

The study tests the extent to which primary care physician supply (office based primary care physicians per 10 000 population) moderates the association between social inequalities and infant mortality and low birth weight throughout the 50 states of the USA.

DESIGN

Pooled cross sectional, time series analysis of secondary data. Analyses controlled for state level education, unemployment, racial/ethnic composition, income inequality, and urban/rural differences. Contemporaneous and time lagged covariates were modelled.

SETTING

Eleven years (1985-95) of data from 50 US states (final n = 549 because of one missing data point).

MAIN RESULTS

Primary care was negatively associated with infant mortality and low birth weight in all multivariate models (p<0.0001). The association was consistent in contemporaneous and time lagged models. Although income inequality was positively associated with low birth weight and infant mortality (p<0.0001), the association with infant mortality disappeared with the addition of sociodemographic covariates.

CONCLUSIONS

In US states, an increased supply of primary care practitioners-especially in areas with high levels of social disparities-is negatively associated with infant mortality and low birth weight.

Income inequality and health: a critical review of the literature

This article critically reviews published literature on the relationship between income inequality and health outcomes. Studies are systematically assessed in terms of design, data quality, measures, health outcomes, and covariates analyzed. At least 33 studies indicate a significant association between income inequality and health outcomes, while at least 12 studies do not find such an association. Inconsistencies include the following: (1) the model of health determinants is different in nearly every study, (2) income inequality measures and data are inconsistent, (3) studies are performed on different combinations of countries and/or states, (4) the time period in which studies are conducted is not consistent, and (5) health outcome measures differ. The relationship between income inequality and health is unclear. Future studies will require a more comprehensive model of health production that includes health system covariates, sufficient sample size, and adjustment for inconsistencies in income inequality data.

Is income inequality a determinant of population health? Part 1. A systematic review

This article reviews 98 aggregate and multilevel studies examining the associations between income inequality and health. Overall, there seems to be little support for the idea that income inequality is a major, generalizable determinant of population health differences within or between rich countries. Income inequality may, however, directly influence some health outcomes, such as homicide in some contexts. The strongest evidence for direct health effects is among states in the United States, but even that is somewhat mixed. Despite little support for a direct effect of income inequality on health per se, reducing income inequality by raising the incomes of the most disadvantaged will improve their health, help reduce health inequalities, and generally improve population health.

Primary care, income inequality, and stroke mortality in the United States: a longitudinal analysis, 1985-1995

BACKGROUND AND PURPOSE

The goal of this study was to test whether primary care reduces the impact of income inequality on stroke mortality.

METHODS

This study used pooled time-series cross-sectional analysis of 11 years of state-level data (n=549). Analyses controlled for education levels, unemployment, racial/ethnic composition, and percent urban. Contemporaneous and time-lagged covariates were modeled.

RESULTS

Primary care was negatively associated with stroke mortality in models including all covariates (P<0.0001). The impact of income inequality on stroke mortality was reduced in the presence of primary care (P<0.0001) but disappeared with the addition of covariates (P>0.05).

CONCLUSIONS

In the absence of social policy that addresses sociodemographic determinants of health, primary care promotion may serve as a palliative strategy for combating stroke mortality and reducing the adverse impact of income inequality on health.

An ecological study of the relationship between social and environmental determinants of obesity

There is growing concern with the increasing prevalence of obesity in industrialised countries, a trend that is more apparent in the poor than in the rich. In an ecological study, the relationship between an area measure of socioeconomic status (SES) and the density of fast-food outlets was examined as one possible explanation for the phenomenon. It was found that there was a dose-response between SES and the density of fast-food outlets, with people living in areas from the poorest SES category having 2.5 times the exposure to outlets than people in the wealthiest category. The findings are discussed.

Letting the Gini out of the bottle? Challenges facing the relative income hypothesis

The relative income hypothesis interprets statistical associations between income inequality and average health status at the population level, as evidence that income inequality has a deleterious psychosocial effect on individual health. An alternative explanation is that these, population-level associations, are statistical artefacts of curvilinear, individual-level relationships between income and health. Indeed, provided the cost-benefit ratio of health-enhancing goods and services vary, the law of diminishing returns should produce curvilinear, asymptotic relationships between income and health at the individual level, which create ('artefactual') associations between income inequality and health at the population level. However, proponents of the relative income hypothesis have argued that these relationships are unlikely to be responsible for the associations observed between income inequality and average health status amongst high-income populations. In these populations, the individual-level relationships between income and health would be nearer their asymptotes, where a shallower slope should ensure that income inequality has little (if any) 'artefactual' effect on average health status. Yet this argument was based on analyses of population-level data which underestimated the slope and curvilinearity of underlying, individual-level relationships between income and health. It is therefore likely that (at least some part of) the population-level associations between income inequality and average health status (amongst low-, middle- and high-income populations) are 'artefacts' of curvilinear, individual-level relationships between income and health. Nevertheless, it is also possible that income inequality is somehow (partly or wholly) responsible for the curvilinear nature of individual-level relationships between income and health. Likewise, it is possible that income inequality alters the height, slope and/or curvilinearity of these relationships in such a way that income inequality has an independent effect on individual health. In either instance, the 'artefactual' effect of curvilinear relationships between income and health at the individual level would simply reflect the mechanism underlying the relative income hypothesis.

The differential effect of education and occupation on body mass and overweight in a sample of working people of the general population

PURPOSE

To assess whether two indicators of social class, education and occupation, have independent and/or synergistic effects in determining the body mass and overweight.

METHODS

Body mass index (BMI), education, and occupation were assessed in a survey of 1767 men and 1268 women from a representative sample of currently working people of the general population of Geneva, Switzerland. Education and occupation were categorized as low, medium, and high. Overweight was defined as BMI > or = 25 kg/m(2).

RESULTS

The prevalence of overweight was 52.1% in men and 28.7% in women. Men with overweight were more likely to have low education while women with overweight had lower education and lower occupation. Education and occupation were inversely related to BMI in both genders and, in women, had a synergistic effect (p-value for the interaction = 0.03).

CONCLUSIONS

Education and occupation have independent and, in women, synergistic effects on BMI. The two indicators may express different mechanisms through which low social class is related to high body mass.

[Factors associated with the accumulation of abdominal fat estimated with anthropometric indexes]

BACKGROUND

To evaluate lifestyle and dietary intake factors influencing the accumulation of abdominal fat in a Mediterranean population.

SUBJECTS AND METHOD

A cross-sectional study was carried-out in Spain (Asturias, Granada, Murcia, Navarra and Guipuzkoa) among 23,228 women and 14,332 men aged 29-69 years, participants of a large European prospective cohort (EPIC). Information on usual food intake and other non-dietary factors were collected by interviews. Height, weight, waist circumference and hip circumference were taken by previously trained interviewers.

RESULTS

In a multiple-linear regression analysis sports activities and educational level were negatively associated with abdominal obesity, while body mass index, age, tobacco and alcohol consumption, saturated fat intake and increased prevalence of hypertension, diabetes and myocardial infarction were positively associated. All dietary and non-dietary variables accounted for 22 and 27% of variance in the waist/hip ratio and 74 and 66% of variance in the waist circumference, in women and men respectively.

CONCLUSIONS

Body mass index and age are the most important factors influencing the accumulation of abdominal fat. Dietary factors and other lifestyle factors seem to play a minor role in increasing abdominal obesity.