George A. Kaplan

Socioeconomic factors and cardiovascular disease: a review of the literature.

Despite recent declines in mortality, cardiovascular diseases are the leading cause of death in the United States today. It appears that many of the major risk factors for coronary disease have been identified. Researchers are still learning about different modifiable factors that may influence cardiovascular diseases. Socioeconomic status may provide a new focus. The principal measures of SES have been education, occupation, and income or combinations of these. Education has been the most frequent measure because it does not usually change (as occupation or income might) after young adulthood, information about education can be obtained easily, and it is unlikely that poor health in adulthood influences level of education. However, other measures of SES have merit, and the most informative strategy would incorporate multiple indicators of SES. A variety of psychosocial measures--for example, certain aspects of occupational status--may be important mediators of SES and disease. The hypothesis that high job strain may adversely affect health status has a rational basis and is supported by evidence from a limited number of studies. There is a considerable body of evidence for a relation between socioeconomic factors and all-cause mortality. These findings have been replicated repeatedly for 80 years across measures of socioeconomic level and in geographically diverse populations. During 40 years of study there has been a consistent inverse relation between cardiovascular disease, primarily coronary heart disease, and many of the indicators of SES. Evidence for this relation has been derived from prevalence, prospective, and retrospective cohort studies. Of particular importance to the hypothesis that SES is a risk factor for cardiovascular disease was the finding by several investigators that the patterns of association of SES with coronary disease had changed in men during the past 30 to 40 years and that SES has been associated with the decline of coronary mortality since the mid-1960s. However, the declines in coronary mortality of the last few decades have not affected all segments of society equally. There is some evidence that areas with the poorest socioenvironmental conditions experience later onset in the decline in cardiovascular mortality. A number of studies suggest that poor living conditions in childhood and adolescence contribute to increased risk of arteriosclerosis. Some of these studies have been criticized because of their nature, and others for inadequate control of confounding factors.(ABSTRACT TRUNCATED AT 400 WORDS)

Income inequality and mortality: importance to health of individual income, psychosocial environment, or material conditions

Studies on the health effects of income inequality have generated great interest. The evidence on this association between countries is mixed,1–4 but income inequality and health have been linked within the United States,5–11 Britain,12 and Brazil.13 Questions remain over how to interpret these findings and the mechanisms involved. We discuss three interpretations of the association between income inequality and health: the individual income interpretation, the psychosocial environment interpretation, and the neo-material interpretation. #### Summary points Income inequality has generally been associated with differences in health A psychosocial interpretation of health inequalities, in terms of perceptions of relative disadvantage and the psychological consequences of inequality, raises several conceptual and empirical problems Income inequality is accompanied by many differences in conditions of life at the individual and population levels, which may adversely influence health Interpretation of links between income inequality and health must begin with the structural causes of inequalities, and not just focus on perceptions of that inequality Reducing health inequalities and improving public health in the 21st century requires strategic investment in neo-material conditions via more equitable distribution of public and private resources We reviewed the literature through traditional and electronic means and supplemented this with correlational analyses of gross domestic product and life expectancy and of income inequality and mortality trends based on data from the World Bank,14 the World Health Organization,15 and two British sources.16 17 According to the individual income interpretation, aggregate level associations between income inequality and health reflect only the individual level association between income and health. The curvilinear relation between income and health at the individual level 18 19 is a sufficient condition to produce health differences between populations with the same average income but different distributions of income.3 20 This interpretation assumes that determinants …

Inequality in income and mortality in the United States: analysis of mortality and potential pathways

Abstract Objective: To examine the relation between health outcomes and the equality with which income is distributed in the United States. Design: The degree of income inequality, defined as the percentage of total household income received by the less well off 50% of households, and changes in income inequality were calculated for the 50 states in 1980 and 1990. These measures were then examined in relation to all cause mortality adjusted for age for each state, age specific deaths, changes in mortalities, and other health outcomes and potential pathways for 1980, 1990, and 1989-91. Main outcome measure: Age adjusted mortality from all causes. Results: There was a significant correlation (r=0.62, P<0.001) between the percentage of total household income received by the less well off 50% in each state and all cause mortality, unaffected by adjustment for state median incomes. Income inequality was also significantly associated with age specific mortalities and rates of low birth weight, homicide, violent crime, work disability, expenditures on medical care and police protection, smoking, and sedentary activity. Rates of unemployment, imprisonment, recipients of income assistance and food stamps, lack of medical insurance, and educational outcomes were also worse as income inequality increased. Income inequality was also associated with mortality trends, and there was a suggestion of an impact of inequality trends on mortality trends. Conclusions: Variations between states in the inequality of the distribution of income are significantly associated with variations between states in a large number of health outcomes and social indicators and with mortality trends. These differences parallel relative investments in human and social capital. Economic policies that influence income and wealth inequality may have an important impact on the health of countries. Key messages There was a significant correlation (r=0.62) between the proportion of total household income received by the less well off 50% of households and variation between states in death rates for the United States Income inequality was also significantly related to changes in mortality with smaller declines between 1980-90 in those states with greater income inequality Income inequality was associated with a large number of other health outcomes and with measures related to investments in human and social capital Economic policies that increase income inequality may also have a deleterious effect on population health

Why do poor people behave poorly? Variation in adult health behaviours and psychosocial characteristics by stages of the socioeconomic lifecourse.

Attempts to explain socioeconomic inequalities in health have often made reference to the observation that poor health behaviours and psychosocial characteristics cluster in low socioeconomic status (SES) groups. Causal interpretation of the association between SES, health behaviour, psychosocial orientations, and health inequalities has been hampered because these factors and SES have usually been measured at the same point in time. Data from the Kuopio Ischaemic Heart Disease Risk Factor Study were used to examine the associations between measures of SES reflecting different stages of the lifecourse, health behaviours, and psychosocial characteristics in adulthood in a population-based study of 2674 middle-aged Finnish men. Results show that many adult behaviours and psychosocial dispositions detrimental to health are consistently related to poor childhood conditions, low levels of education, and blue-collar employment. Poor adult health behaviours and psychosocial characteristics were more prevalent among men whose parents were poor. Increases in income inequality which place children into low SES conditions may well produce a negative behavioural and psychosocial health dividend to be reaped in the future. Understanding that adult health behaviour and psychosocial orientations are associated with socioeconomic conditions throughout the lifecourse implies that efforts to reduce socioeconomic inequalities in health must recognize that economic policy is public health policy.

Cumulative impact of sustained economic hardship on physical, cognitive, psychological, and social functioning.

BACKGROUND Although the relation between low income and poor health is well established, most previous research has measured income at only one time. METHODS We used income information collected in 1965, 1974, and 1983 from a representative sample of adults in Alameda County, California, to examine the cumulative effect of economic hardship (defined as a total household income of less than 200 percent of the federal poverty level) on participants who were alive in 1994. RESULTS Because of missing information, analyses were based on between 1081 and 1124 participants (median age, 65 years in 1994). After adjustment for age and sex, there were significant graded associations between the number of times income was less than 200 percent of the poverty level (range, 0 to 3) and all measures of functioning examined except social isolation. As compared with subjects without economic hardship, those with economic hardship in 1965, 1974, and 1983 were much more likely to have difficulties with independent activities of daily living (such as cooking, shopping, and managing money) (odds ratio, 3.38; 95 percent confidence interval, 1.49 to 7.64), activities of daily living (such as walking, eating, dressing, and using the toilet) (odds ratio, 3.79; 95 percent confidence interval, 1.32 to 9.81), and clinical depression (odds ratio, 3.24; 95 percent confidence interval, 1.32 to 7.89) in 1994. We found little evidence of reverse causation -- that is, that episodes of illness might have caused subsequent economic hardship. CONCLUSIONS Sustained economic hardship leads to poorer physical, psychological, and cognitive functioning.

Frequent attendance at religious services and mortality over 28 years.

OBJECTIVES This study analyzed the long-term association between religious attendance and mortality to determine whether the association is explained by improvements in health practices and social connections for frequent attenders. METHODS The association between frequent attendance and mortality over 28 years for 5286 Alameda Country Study respondents was examined. Logistic regression models analyzed associations between attendance and subsequent improvements in health practices and social connections. RESULTS Frequent attenders had lower mortality rates than infrequent attenders (relative hazard [RH] = 0.64;95% confidence interval [CI] = 0.53,0.77). Results were stronger for females. Health adjustments had little impact, but adjustments for social connections and health practices reduced the relationship (RH = 0.77; 95% CI = 0.64, 0.93). During follow-up, frequent attenders were more likely to stop smoking, increase exercising, increase social contacts, and stay married. CONCLUSIONS Lower mortality rates for frequent religious attenders are partly explained by improved health practices, increased social contacts, and more stable marriages occurring in conjunction with attendance. The mechanisms by which these changes occur have broad intervention implications.

Prospective association between obesity and depression: evidence from the Alameda County Study

OBJECTIVE: To examine the temporal relation between obesity and depression to determine if each constitutes a risk factor for the other.DESIGN: A two-wave, 5-y-observational study with all measures at both times.SUBJECTS: A total of 2123 subjects, 50 y of age and older, who participated in the 1994 and 1999 waves of the Alameda County Study.MEASUREMENTS: Obesity defined as body mass index (BMI)⩾30. Depression assessed using DSM-IV symptom criteria for major depressive episodes. Covariates include indicators of age, gender, education, marital status, social support, life events, physical health problems, and functional limitations.RESULTS: Obesity at baseline was associated with increased risk of depression 5 y later, even after controlling for depression at baseline and an array of covariates. The reverse was not true; depression did not increase the risk of future obesity.CONCLUSION: These results, the first ever on reciprocal effects between obesity and depression, add to a growing body of evidence concerning the adverse effects of obesity on mental health. More studies are needed on the relation between obesity and mental health and implications for prevention and treatment.

Income inequality and mortality in metropolitan areas of the United States.

OBJECTIVES This study examined associations between income inequality and mortality in 282 US metropolitan areas. METHODS Income inequality measures were calculated from the 1990 US Census. Mortality was calculated from National Center for Health Statistics data and modeled with weighted linear regressions of the log age-adjusted rate. RESULTS Excess mortality between metropolitan areas with high and low income inequality ranged from 64.7 to 95.8 deaths per 100,000 depending on the inequality measure. In age-specific analyses, income inequality was most evident for infant mortality and for mortality between ages 15 and 64. CONCLUSIONS Higher income inequality is associated with increased mortality at all per capita income levels. Areas with high income inequality and low average income had excess mortality of 139.8 deaths per 100,000 compared with areas with low inequality and high income. The magnitude of this mortality difference is comparable to the combined loss of life from lung cancer, diabetes, motor vehicle crashes, human immunodeficiency virus (HIV) infection, suicide, and homicide in 1995. Given the mortality burden associated with income inequality, public and private sector initiatives to reduce economic inequalities should be a high priority.

Hopelessness and Risk of Mortality and Incidence of Myocardial Infarction and Cancer

We examined the relationship among low, moderate, and high levels of hopelessness, all-cause and cause-specific mortality, and incidence of myocardial infarction (MI) and cancer in a population-based sample of middle-aged men. Participants were 2428 men, ages 42 to 60, from the Kuopio Ischemic Heart Disease study, an ongoing longitudinal study of unestablished psychosocial risk factors for ischemic heart disease and other outcomes. In 6 years of follow-up, 174 deaths (87 cardiovascular and 87 noncardiovascular, including 40 cancer deaths and 29 deaths due to violence or injury), 73 incident cancer cases, and 95 incident MI had occurred. Men were rated low, moderate, or high in hopelessness if they scored in the lower, middle or upper one-third of scores on a 2-item hopelessness scale. Age-adjusted Cox proportional hazards models identified a dose-response relationship such that moderately and highly hopeless men were at significantly increased risk of all-cause and cause-specific mortality relative to men with low hopelessness scores. Indeed, highly hopeless men were at more than three-fold increased risk of death from violence or injury compared with the reference group. These relationships were maintained after adjusting for biological, socioeconomic, or behavioral risk factors, perceived health, depression, prevalent disease, or social support. High hopelessness also predicted incident MI, and moderate hopelessness was associated with incident cancer. Our findings indicate that hopelessness is a strong predictor of adverse health outcomes, independent of depression and traditional risk factors. Additional research is needed to examine phenomena that lead to hopelessness.

Epidemiologic evidence for the relation between socioeconomic status and depression, obesity, and diabetes

Many of the leading causes of death and disability in the United States and other countries are associated with socioeconomic position. The least well-off suffer a disproportionate share of the burden of disease, including depression, obesity, and diabetes. Research suggests that the adverse effects of economic hardship on both mental and physical health and functioning are evident at young ages and persist across the lifecourse. Moreover, these associations are seen across cultures. Data from four large epidemiologic studies on the role of psychological characteristics, social factors, and behaviors in health and disease risk are presented that highlight the striking associations between socioeconomic factors and chronic diseases. Data from these studies demonstrate that the effects of economic disadvantage are cumulative, with the greatest risk of poor mental and physical health seen among those who experienced sustained hardship over time.