Extending the income inequality hypothesis: Ecological results from the 2005 and 2009 Argentine National Risk Factor Surveys

Abstract

A consensus on income inequality as a social determinant of health is yet to be reached. In particular, we know little about the cross-sectional versus lagged effect of inequality and the robustness of the relationship to indicators that are sensitive to varying parts of the income spectrum. We test these issues with data from Argentina's 2005 and 2009 National Risk Factor Surveys. Inequality was operationalised at the provincial level with the Gini coefficient and the Generalised Entropy (GE) index. Population health was defined as the age-standardised percentage of adults with poor/fair self-rated health by province. Our cross-sectional results indicate a significant relationship between inequality (Gini) and poor health (r=0.58, p<0.01) in 2005. Using the GE index, a gradient pattern emerges in the correlation, and the r values increase as the index becomes sensitive to the top of the distribution. The relationship between 2005 inequality and 2009 health displays a similar pattern, but with generally smaller correlations than the 2005 cross-sectional results. Further advances in the income inequality and health literature require new theoretical models to account for how inequalities in different parts of the income spectrum may influence population health in different ways.     

Peripherality, income inequality, and life expectancy: revisiting the income inequality hypothesis

BACKGROUND: Recent criticisms of the income inequality and health hypothesis have stressed the lack of consistent significant evidence for the stronger effects of income inequality among rich countries. Despite such criticisms, little attention has been devoted to the income-based criteria underlying the stratification of countries into rich/poor groups and whether trade patterns and world-system role provide an alternative means of stratifying groups. METHODS: To compare income-based and trade-based criteria, 107 countries were grouped into four typologies: (I) high/low income, (II) OECD membership/non-membership, (III) core/non-core, and (IV) non-periphery/periphery. Each typology was tested separately for significant differences in the effects of income inequality between groups. Separate group comparison tests and regression analyses were conducted for each typology using Rodgers (1979) specification of income, income inequality, and life expectancy. Interaction terms were introduced into Rodgers specification to test whether group classification moderated the effects of income inequality on health. RESULTS: Results show that the effects of income inequality are stronger in the periphery than non-periphery (IV) (-0.76 vs -0.23; P < 0.05). An incremental F-test confirmed significant differences in the coefficient subsets between the two groups (F(2,101) = 6.31; P < 0.01). CONCLUSIONS: Cross-national analyses of income inequality and population health have assumed (i) income differences between countries best capture global stratification and (ii) the negative effects of income inequality are stronger in high-income countries. However, present findings emphasize (i) the importance of measuring global stratification according to trading patterns and (ii) the strong, negative effects of income inequality on life expectancy among peripheral populations.     

Beyond the income inequality hypothesis: class, neo-liberalism, and health inequalities

This paper describes and critiques the income inequality approach to health inequalities. It then presents an alternative class-based model through a focus on the causes and not only the consequences of income inequalities. In this model, the relationship between income inequality and health appears as a special case within a broader causal chain. It is argued that global and national socio-political-economic trends have increased the power of business classes and lowered that of working classes. The neo-liberal policies accompanying these trends led to increased income inequality but also poverty and unequal access to many other health-relevant resources. But international pressures towards neo-liberal doctrines and policies are differentially resisted by various nations because of historically embedded variation in class and institutional structures. Data presented indicates that neo-liberalism is associated with greater poverty and income inequalities, and greater health inequalities within nations. Furthermore, countries with Social Democratic forms of welfare regimes (i.e., those that are less neo-liberal) have better health than do those that are more neo-liberal. The paper concludes with discussion of what further steps are needed to "go beyond" the income inequality hypothesis towards consideration of a broader set of the social determinants of health.     

Modelling health,income and income inequality: the impact of income inequality on health and health inequality

A framework is developed to analyse the impact of the distribution of income on individual health and health inequality, with individual health modelled as a function of income and the distribution of income. It is demonstrated that the impact of income inequality can generate non-concave health production functions resulting in a non-concave health production possibility frontier. In this context, the impact of different health policies are considered and it is argued that if the distribution of income affects individual health, any policy aimed at equalising health, which does not account for income inequality, will lead to unequal distributions of health. This is an important development given current UK government attention to reducing health inequality.     

Child wellbeing and income inequality in rich societies: ecological cross sectional study

Child wellbeing and income inequality in rich societies: ecological cross sectional study .
Pickett K.E. & Wilkinson R.G. ( 2007 ) British Medical Journal , 335 , 1080 – 1085 . DOI: 10.1136/bmj.39377.580162.55.     

Global variations in health: Evaluating Wilkinson's income inequality hypothesis using the World Values Survey

This international comparative study analyses individual-level data derived from the World Values Survey to evaluate Wilkinson's [(1996). Unhealthy societies: The afflictions of inequality. London: Routledge; (1998). Mortality and distribution of income. Low relative income affects mortality [letter; comment]. British Medical Journal, 316, 1611–1612] income inequality hypothesis regarding variations in health status. Random-coefficient, multilevel modelling provides a direct test of Wilkinson's hypothesis using micro-data on individuals and macro-data on income inequalities analysed simultaneously. This overcomes the ecological fallacy that has troubled previous research into links between individual self-rated health, individual income, country income and income inequality data. Logic regression analysis reveals that there are substantial differences between countries in self-rated health after taking account of age and gender, and individual income has a clear effect in that poorer people report experiencing worse health. The Wilkinson hypothesis is not supported, however, since there is no significant relationship between health and income inequality when individual factors are taken into account. Substantial differences between countries remain even after taking account of micro- and macro-variables; in particular the former communist countries report high levels of poor health.     

Peer Reviewed: Tracking Chronic Disease and Risk Behavior Prevalence as Survey Participation Declines: Statistics From the Behavioral Risk Factor Surveillance System and Other National Surveys

Introduction

Response rates for the Behavioral Risk Factor Surveillance System (BRFSS) have declined in recent years. The response rate in 1993 was approximately 72%; in 2006, the response rate was approximately 51%. To assess the impact of this decline on the quality of BRFSS estimates, we compared selected health and risk factor estimates from BRFSS with similar estimates from the National Health Interview Survey (NHIS) and the National Health and Nutrition Examination Survey (NHANES).

Methods

We reviewed questionnaires from the 3 surveys and identified a set of comparable measures related to smoking prevalence, alcohol consumption, medical conditions, vaccination, health status, insurance coverage, cost barriers to medical care, testing for human immunodeficiency virus, and body measurements (height and weight).We compared weighted estimates for up to 15 outcome measures, including overall measures and measures for 12 population subgroups. We produced design-appropriate point estimates and carried out statistical tests of hypotheses on the equality of such estimates. We then calculated P values for comparisons of NHIS and NHANES estimates with their BRFSS counterparts.

Results

Although BRFSS and NHIS estimates were statistically similar for 5 of the 15 measures examined, BRFSS and NHANES estimates were statistically similar for only 1 of 6 measures. The observed differences for some of these comparisons were small, however.

Conclusion

These surveys produced similar estimates for several outcome measures, although we observed significant differences as well. Many of the observed differences may have limited consequences for implementing related public health programs; other differences may require more detailed examination. In general, the range of BRFSS estimates examined here tends to parallel those from NHIS and NHANES, both of which have higher rates of participation.     

Dietary and weight control practices among persons with hypertension: findings from the 1986 Behavioral Risk Factor Surveys

The National Heart, Lung, and Blood Institute has concluded that reducing sodium intake, controlling weight, and moderating alcohol consumption can help patients with hypertension control their blood pressure. To determine whether such patients have adopted recommended dietary practices, we analyzed data collected in 1986 from telephone surveys of adults in 26 states (no. = 34,395). The self-reported dietary practices that we evaluated were: use of table salt, alcohol consumption, and weight control practices. In comparison with persons who did not have hypertension (no. = 26,848), those with hypertension who were receiving pharmacological therapy ("treated hypertensives," no. = 5,025) were more likely to report limiting their use of table salt (odds ratio [OR] = 2.5) and were less likely to have their weight controlled (OR = 0.4). Although overweight persons with hypertension were more likely than persons with normal blood pressure to attempt to lose weight, most have not included exercise in their weight loss efforts. There was no difference between persons who do not have hypertension and treated patients with hypertension in their use of alcohol. Untreated persons with hypertension (no. = 2,378) were less likely to limit their use of table salt and less likely to moderate their use of alcohol than treated persons with hypertension but otherwise reported similar dietary practices. Dietetic practitioners may need to emphasize moderation of alcohol use and the use of physical activity to lose weight when counseling patients with hypertension.     

The Meth Project and Teen Meth Use: New Estimates from the National and State Youth Risk Behavior Surveys

In this note, we use data from the national and state Youth Risk Behavior Surveys for the period 1999 through 2011 to estimate the relationship between the Meth Project, an anti‐methamphetamine advertising campaign, and meth use among high school students. During this period, a total of eight states adopted anti‐meth advertising campaigns. After accounting for pre‐existing downward trends in meth use, we find little evidence that the campaign curbed meth use in the full sample. We do find, however, some evidence that the Meth Project may have decreased meth use among White high school students. Copyright © 2014 John Wiley & Sons, Ltd.     

Risk factors for overweight and obesity: results from the 2001 National Health Survey

OBJECTIVES: A significant rise in the proportion of overweight and obese adults has produced a serious health epidemic in Australia and worldwide. The current research aimed to identify sociodemographic and behavioural predictors of overweight and obesity among a large representative sample of Australian adults. STUDY DESIGN: We used the National Health Survey conducted by the Australian Bureau of Statistics in 2001. The survey involved a stratified multistage area sample of private dwellings and face-to-face interviews. METHODS: We analysed data from 8643 females and 7600 males who responded to the 2001 National Health Survey. Multinomial logistic regression examined the association of being overweight or obese versus a healthy weight with a range of sociodemographic and behavioural variables. RESULTS: Fewer females than males were overweight while similar proportions were obese. For females and males, overweight and obesity were significantly associated with older age, being born in Australia, not being in a marriage-like relationship, low education, physical inactivity, and being a non/ex-smoker. High household incomes are protective from obesity but not from being overweight. Additionally, females with high levels of area social disadvantage and males in professional or white-collar occupations were more likely to be overweight or obese than a healthy weight. CONCLUSIONS: Reductions in mortality and morbidity associated with overweight and obesity may be achieved by targeting health promotion strategies to high-risk groups such as those who are older, single, Australian born, socioeconomically disadvantaged, physically inactive, and non-smokers.     

Population health and income inequality: new evidence from Israeli time-series analysis

BACKGROUND AND OBJECTIVES: The relationship between population health and inequality in income distribution has attracted much attention during the last two decades. The purpose of this paper is to examine that relationship using Israeli time-series data, and considering three types of income: economic, pre-tax, and disposable. METHODS: Israeli time series (1979-2000) on life expectancy of men and women at birth and at ages 5 and 65, as well as infant mortality, were related to Gini coefficients measuring inequality in economic, pre-tax (after transfers) and disposable (after taxes) incomes, controlling for gross domestic product (GDP) per capita. This design allows for the estimation of the effects on population health of changes in income inequalities over time as well as of contemporaneous reduction in inequality due to transfers and taxes. RESULTS: None of the three income inequality measures by itself had an effect over time on population health. However, larger contemporaneous reductions in inequality, mainly through the transfers system, were associated with better population health, in particular with lower infant mortality. CONCLUSIONS: A significant part of the temporal improvement in the health of the Israeli population has been due to the increasing effort to reduce inequality in economic income by increasing transfer payments. The results are generally inconsistent with the argument of adverse psychosocial effects of inequality on health, and are consistent with inequality being related to other harmful public goods affecting health and with Rodgers' argument.     

Compositional and contextual approaches to the study of health behaviour and outcomes: using multi-level modelling to evaluate Wilkinson's income inequality hypothesis

Much research into health behaviour and outcomes involves evaluating compositional and contextual hypotheses: the former suggest that behaviour/outcomes are a function of the individual's characteristics alone, whereas the latter argue for the importance of contextual/environmental influences. Wilkinson has presented a contextual argument relating inter-country variations in mortality rates to income inequalities; Gravelle has countered this arguing that Wilkinson's findings are a statistical artefact and that a compositional approach, relating mortality to individual income, is sufficient. Discriminating between these two cases requires a methodology combining the two approaches. Multi-level modelling is proposed and applied to two data sets. The results sustain Gravelle's case, emphasising the role of compositional rather than contextual variables in accounting for inter-country variations in health status.     

Tobacco smoking by occupation in Australia: results from the 2004 to 2005 National Health Survey

OBJECTIVE: This study presents the most recent estimates of Australia's national tobacco smoking rates by occupation. METHODS: Smoking data was extracted from the 2004 to 2005 National Health Survey, which captured approximately 26,000 persons and achieved a response rate of around 90%. Participants were limited to those of working age (18 to 64 years), with data stratified by job category and gender during the analysis. RESULTS: The prevalence of smoking among Australian workers is estimated to be 25% (28% among males and 21% among females). Tobacco usage is considerably less common among those who are employed compared with the unemployed. By job category, smoking was most common among laborers and the least common among professionals, managers, or administrators. CONCLUSIONS: Overall, this study suggests that Australian rates of tobacco smoking vary widely depending on occupation. Effective tobacco-control strategies targeting vulnerable sections of the workforce, particularly blue-collar workers, are clearly needed.     

An economic analysis of adult obesity: results from the Behavioral Risk Factor Surveillance System

This paper examines the factors that may be responsible for the 50% increase in the number of obese adults in the US since the late 1970s. We employ the 1984-1999 Behavioral Risk Factor Surveillance System, augmented with state level measures pertaining to the per capita number of fast-food and full-service restaurants, the prices of a meal in each type of restaurant, food consumed at home, cigarettes, and alcohol, and clean indoor air laws. Our main results are that these variables have the expected effects on obesity and explain a substantial amount of its trend.     

Bullying in Brazilian schools: results from the National School-based Health Survey (PeNSE), 2009

The aim of this study is to identify and describe the occurrence of bullying among students in the 9th year (8th grade) from public and private schools from 26 Brazilian state capitals and the Federal District. It is a cross-sectional study involving 60,973 students and 1,453 public and private schools. Data analysis indicates that 5.4% (IC95%: 5.1%-5.7%) of students reported having suffered bullying almost always or always in the last 30 days, 25.4% (IC95%: 24.8%-26.0%) were rarely or sometimes the victim of bullying and 69.2% (IC95%: 68.5%-69.8%) of students felt no humiliation or provocation at school. The capital with higher frequency of bullying was Belo Horizonte (6.9%; IC95%: 5,9%-7,9%), Minas Gerais, and the lowest was Palmas (3.5%; IC95%: 2.6%-4.5%), Tocantins. Boys reported more bullying (6,0%; IC95%: 5.5%-6.5%) compared with girls (4,8%; IC95%: 4.4%-5.3%). There was no difference between public schools 5.5% (IC95%: 5.1%-5.8%) and private (5.2%) (IC95%: 4.6%-5.8%), except in Aracaju, Sergipe, that show more bullying in private schools. The findings indicate an urgent need for intersectoral action from educational policies and practices that enforce the reduction and prevention of the occurrence of bullying in schools in Brazil.     

Gamma-tocopherol as a possible marker for nutrition-related risk: results from four National Diet and Nutrition Surveys in Britain

Relationships between vitamin E status (alpha and gamma-tocopherol and their ratio in plasma), anthropometric and biochemical indices, and food and nutrient intakes, were studied in four British National Diet and Nutrition Surveys: children aged 1.5-4.5 years, young people aged 4.0-18.0 years, adults 19.0-64.0 years and adults aged > or = 65.0 years. gamma-Tocopherol:alpha-tocopherol ratio declined with age. In older women gamma-tocopherol and gamma-tocopherol:alpha-tocopherol ratios were directly related to indices of obesity. In young men alpha- and gamma-tocopherols were directly correlated with obesity, but gamma-tocopherol:alpha-tocopherol ratio was not. For young people and toddlers, fewer obesity indices were available and relationships were weaker. Other fat- and water-soluble vitamin indices correlated directly with alpha-tocopherol and inversely with gamma-tocopherol and gamma-tocopherol:alpha-tocopherol ratio. Whereas alpha-tocopherol correlated directly with 'healthy' nutrient choices (such as intrinsic sugars, dietary fibre, vitamins and potassium) and inversely with 'unhealthy' choices (extrinsic sugars and monounsaturated fats, i.e. avoidance of polyunsaturated fat), gamma-tocopherol and the gamma-tocopherol:alpha-tocopherol ratio related inversely with 'healthy' choices. Food groups had analogous relationships; thus, alpha-tocopherol related directly to use of polyunsaturated fats, fresh fruits and fruit juices, and inversely to non-polyunsaturated fats and extrinsic sugar. The reverse was true for gamma-tocopherol and gamma-tocopherol:alpha-tocopherol ratio. Although the mechanisms underlying these relationships are obscure, the gamma-tocopherol:alpha-tocopherol ratio may reveal poor dietary choices, status predictors and a propensity for obesity in later life, especially in women.     

Even higher global inequality than previously thought: a note on global inequality calculations using the 2005 International Comparison Program results

Using the new results of the International Comparison Program 2005, the author reestimates inequalities between mean country incomes and global inequality among world citizens. All types of international inequality are found to be greater than previously thought (that is, as calculated using earlier data on countries' price levels). The main reason for the higher inequalities is that domestic price levels in most populous Asian countries (China, India, Philippines, Bangladesh) are some 40 percent higher than previously estimated. This implies not only higher global inequality but significantly greater global poverty head counts.     

Aggregation and the measurement of income inequality: effects on morbidity

This is a cross-sectional study using records from the National Health Interview Survey linked to Census geography. The sample is restricted to white males ages 25-64 in the United States from three years (1989-1991) of the National Health Interview Survey. Perceived health is used to measure morbidity. Individual covariates include income-to-needs ratio, education and occupation. Contextual level measures of income inequality, median household income and percent in poverty are constructed at the US census county and tract level. The association between inequality and morbidity is examined using logistic regression models. Income inequality is found to exert an independent adverse effect on self-rated health at the county level, controlling for individual socioeconomic status and median income or percent poverty in the county. This corresponding effect at the tract level is reduced. Median income or percent poverty and individual socioeconomic status are the dominant correlates of perceived health status at the tract level. These results suggest that the level of geographic aggregation influences the pathways through which income inequality is actualized into an individuals' morbidity risk. At higher levels of aggregation there are independent effects of income inequality, while at lower levels of aggregation, income inequality is mediated by the neighborhood consequences of income inequality and individual processes.