Measurement and explanation of socioeconomic inequality in health with longitudinal data

This paper presents a method to compare indices of inequality in health that are based on short-run and long-run measures of health and income. For pure health inequality (as measured by the Gini coefficient) and income-related health inequality (as measured by the concentration index), we show how measures derived from longitudinal data can be related to cross section Gini and concentration indices that have been typically reported in the literature to date, along with measures of health mobility inspired by the literature on income mobility. We also show how these measures of mobility can be usefully decomposed into the contributions of different factors. We apply these methods to investigate the degree of income-related mobility in the GHQ measure of psychological well-being in the first nine waves of the British Household Panel Survey (BHPS). This reveals that dynamics increase the absolute value of the concentration index of GHQ on income by 15%, or 1.7% per year on average, for men, and 5%, or 0.6% per year, for women.     

Ageing and health care expenditure in EU-15

The purpose of this paper is to investigate the relationship between ageing and the evolution of health care expenditure per capita in the EU-15 countries. A secondary purpose is to produce estimates that can be used in projections of future health care costs. Explanatory variables include economic, social, demographic and institutional variables as well as variables related to capacity and production technology in the health care sector. The study applies a co-integrated panel data regression approach to derive short-run relationships and furthermore reports long-run relationships between health care expenditure and the explanatory variables. Our findings suggest that there is a positive short-run effect of ageing on health care expenditure, but that the long-run effect of ageing is approximately zero. We find life expectancy to be a more important driver. Although the short-run effect of life expectancy on expenditure is approximately zero, we find that the long-run effect is positive, so that increasing life expectancy leads to a more than proportional, i.e. exponential, increase in health care expenditure.     

Critically examining diversity in end-of-life family caregiving: implications for equitable caregiver support and Canada’s Compassionate Care Benefit

Background

Mental health is of special importance regarding socioeconomic inequalities in health. On the one hand, mental health status mediates the relationship between economic inequality and health; on the other hand, mental health as an "end state" is affected by social factors and socioeconomic inequality. In spite of this, in examining socioeconomic inequalities in health, mental health has attracted less attention than physical health. As a first attempt in Iran, the objectives of this paper were to measure socioeconomic inequality in mental health, and then to untangle and quantify the contributions of potential determinants of mental health to the measured socioeconomic inequality.

Methods

In a cross-sectional observational study, mental health data were taken from an Urban Health Equity Assessment and Response Tool (Urban HEART) survey, conducted on 22 300 Tehran households in 2007 and covering people aged 15 and above. Principal component analysis was used to measure the economic status of households. As a measure of socioeconomic inequality, a concentration index of mental health was applied and decomposed into its determinants.

Results

The overall concentration index of mental health in Tehran was -0.0673 (95% CI = -0.070 - -0.057). Decomposition of the concentration index revealed that economic status made the largest contribution (44.7%) to socioeconomic inequality in mental health. Educational status (13.4%), age group (13.1%), district of residence (12.5%) and employment status (6.5%) also proved further important contributors to the inequality.

Conclusions

Socioeconomic inequalities exist in mental health status in Iran's capital, Tehran. Since the root of this avoidable inequality is in sectors outside the health system, a holistic mental health policy approach which includes social and economic determinants should be adopted to redress the inequitable distribution of mental health.     

Decomposing socioeconomic inequality in infant mortality in Iran

BACKGROUND: Although measuring socioeconomic inequality in population health indicators like infant mortality is important, more interesting for policy purposes is to try to explain infant mortality inequality. The objective of this paper is to quantify for the first time the determinants' contributions of socioeconomic inequality in infant mortality in Iran. METHODS: A nationally representative sample of 108 875 live births from October 1990 to September 1999 was selected. The data were taken from the Iranian Demographic and Health Survey (DHS) conducted in 2000. Households' socioeconomic status was measured using principal component analysis. The concentration index of infant mortality was used as our measure of socioeconomic inequality and decomposed into its determining factors. RESULTS: The largest contributions to inequality in infant mortality were owing to household economic status (36.2%) and mother's education (20.9%). Residency in rural/urban areas (13.9%), birth interval (13.0%), and hygienic status of toilet (11.9%) also proved important contributors to the measured inequality. CONCLUSIONS: The findings indicate that socioeconomic inequality in infant mortality in Iran is determined not only by health system functions but also by factors beyond the scope of health authorities and care delivery system. This implies that in addition to reducing inequalities in wealth and education, investments in water and sanitation infrastructure and programmes (especially in rural areas) are necessary to realize improvements of inequality in infant mortality across society. These findings can be instrumental for the recent 5 year Economic, Social and Cultural Development Plan of Iran, which identified the reduction of inequalities in social determinants of health.     

Health care expenditure and income in Europe

In this work we have tried to analyse the variations in health care expenditure in all the countries of the European Community except Greece and Portugal. We have wanted to provide additional evidence on the empirical relationship between expenditure on health care and income. Our analysis, starting from the approach of Fuchs and Baumol, has been an extension of the traditional studies on health care international comparisons, in at least three directions: we have not imposed any restrictions on the price effects, we have analysed dynamic models instead of the cross-sectional analysis and we have used proper deflators. We have deflated health care expenditure in each country by means of its sectoral price index and by the purchasing parity power of its currency, to allow international comparisons. In the former case we express health care in terms of ‘expenditure’, in the latter we express health care in terms of ‘weighted quantity’. Income elasticities, in the short and in the long-run, have been estimated using econometric methods that allow us to obtain simultaneously equilibrium long-run relationships, if any, and adjustment processes in the short-run. We have found cointegrating relationships and we have estimated consistent estimators of the elasticities. The estimated income elasticities are greater than one in all the models analysed.     

Income inequality and pregnancy spacing

We examined the relationship between county-level income inequality and pregnancy spacing in a welfare-recipient cohort in Washington State. We identified 20,028 welfare-recipient women who had at least one birth between July 1, 1992, and December 31, 1999, and followed this cohort from the date of that first in-study birth until the occurrence of a subsequent pregnancy or the end of the study period. Income inequality was measured as the proportion of total county income earned by the wealthiest 10% of households in that county compared to that earned by the poorest 10%. To measure the relationship between income inequality and the time-dependent risk (hazard) of a subsequent pregnancy, we used Cox proportional hazards methods and adjusted for individual- and county-level covariates. Among women aged 25 and younger at the time of the index birth, the hazard ratio (HR) of subsequent pregnancy associated with income inequality was 1.24 (95% CI: 0.85, 1.80), controlling for individual-level (age, marital status, education at index birth; race, parity) and community-level variables. Among women aged 26 or older at the time of the index birth, the adjusted HR was 2.14 (95% CI: 1.09, 4.18). While income inequality is not the only community-level feature that may affect health, among women aged 26 or older at the index birth it appears to be associated with hazard of a subsequent pregnancy, even after controlling for other factors. These results support previous findings that income inequality may impact health, perhaps by influencing health-related behaviors.     

The effect of changes in health sector resources on infant mortality in the short-run and the long-run: A longitudinal econometric analysis

While countries with higher levels of human resources for health typically have better population health, the evidence that increases in the level of human resources for health leads to improvements in population health is limited. We use a dynamic regression model to obtain estimates of both the short-run and long-term effects of changes in physicians per capita, our measure of health system resources, on infant mortality. Using a dataset of 99 countries at 5-year intervals from 1960–2000, we estimate that increasing the number of physicians by one per 1000 population (roughly a doubling of current levels of provision) decreases the infant mortality rate by 15% within 5 years and by 45% in the long-run with half the long-run gain being achieved in 15 years. We conclude that the long-run effects of heath system resources are substantially larger than previously estimated. Our results suggest, however, that countries that have delayed action on the Millennium Development Goal of reducing infant and child mortality rate by two-thirds by 2015 (relative to 1990) may have difficulty meeting this goal even if they rapidly increase resources now.     

Income inequality and adult nutritional status: anthropometric evidence from a pre-industrial society in the Bolivian Amazon

Evidence has been accumulated about the adverse effects of income inequality on individual health in industrial nations, but we know less about its effect in small-scale, pre-industrial rural societies. Income inequality should have modest effects on individual health. First, norms of sharing and reciprocity should reduce the adverse effects of income inequality on individual health. Second, with sharing and reciprocity, personal income will spill over to the rest of the community, attenuating the protective role of individual income on individual health found in industrial nations. We test these ideas with data from Tsimane' Amerindians, a foraging and farming society in the Bolivian Amazon. Subjects included 479 household heads (13+ years of age) from 58 villages. Dependent variables included anthropometric indices of short-run nutritional status (body-mass index (BMI), and age- and sex-standardized z-scores of mid-arm muscle area and skinfolds). Proxies for income included area deforested per person the previous year and earnings per person in the last 2 weeks. Village income inequality was measured with the Gini coefficient. Income inequality did not correlate with anthropometric indices, most likely because of negative indirect effects from the omission of social-capital variables, which would lower the estimated impact of income inequality on health. The link between BMI and income and between skinfolds and income resembled a U and an inverted U; income did not correlate with mid-arm muscle area. The use of an experimental research design might allow for better estimates of how income inequality affects social capital and individual health.     

Economic evaluation of innovative technologies in health care should include a short-run perspective

Knowledge about the cost-effectiveness of innovative technologies or new guidelines in health care is more and more a necessary condition for implementation in common practice. However, there are situations where implementation of a new technology that is found more effective and cost effective and is strongly advocated by the medical profession stagnates. The reason for this is the discrepancy between long-run efficiency, on which cost effectiveness is based, and short-run efficiency. This paper addresses the potential paradox between long-run and short-run efficiency in health care and explores possibilities to overcome hurdles to implementation due to that paradox.     

Proportional treatment effects for count response panel data: effects of binary exercise on health care demand

We define conditional and marginal treatment effects appropriate for count data, and then conduct an empirical analysis for the effects of exercise on health care demand using panel data from the Health Retirement Study. The response variables are office visits to doctors and hospitalization days, and the treatments of interest are light and vigorous exercises. We found that short-run light exercise increases health care demand by 3-5%, whereas long-run light exercise decreases it by 3-6%. We also found that short-run vigorous exercise decreases health care demand by 1-2%, whereas long-run vigorous exercise decreases it by 1-3%. However, many of these numbers are not statistically significantly different from zero. These findings suggest that it will be difficult to reduce health care cost much by encouraging people to do more exercise--at least in the short-run.     

Longitudinal methods to investigate the role of health determinants in the dynamics of income-related health inequality

The usual starting point for understanding changes in income-related health inequality (IRHI) over time has been regression-based decomposition procedures for the health concentration index. However the reliance on repeated cross-sectional analysis for this purpose prevents both the appropriate specification of the health function as a dynamic model and the identification of important determinants of the transition processes underlying IRHI changes such as those relating to mortality. This paper overcomes these limitations by developing alternative longitudinal procedures to analyse the role of health determinants in driving changes in IRHI through both morbidity changes and mortality, with our dynamic modelling framework also serving to identify their contribution to long-run or structural IRHI. The approach is illustrated by an empirical analysis of the causes of the increase in IRHI in Great Britain between 1999 and 2004.     

A model to correct for short-run inefficiencies in economic evaluations in healthcare

Important assumptions that underlie cost-effectiveness analysis (CEA) are that production technologies are convex and that production processes always perform at constant returns to scale. However, in the short run these assumptions are likely to be violated. Therefore, CEAs might overestimate cost-effectiveness in the short run. To come up with a more precise cost-effectiveness outcome, we present a model that is able to correct the long-run incremental net benefit (INB) for short-run inefficiencies. This provides decision makers with a more realistic view of the expected efficiency gains. This model starts by determining the initial efficiency losses inflicted by inflexible resources. Then the model is made dynamic in order to adjust the efficiency losses by allowing for refilling and writing off freed capacity. Finally, the model calculates the length of the short-run time frame in which such efficiency losses exist, and a correction term with which the usual long-run INB should be adjusted to account for short-run inefficiencies. The model is applied to two cases: dialysis and digitizing a radiography department. The dialysis case shows moderate short-run efficiency losses while in the radiography case short-run efficiency losses are sufficiently large to cause a switch in cost-effectiveness from favorable to inefficient in the short run.     

Does income‐related health inequality change as the population ages? Evidence from Swedish panel data

This paper explains and empirically assesses the channels through which population aging may impact on income‐related health inequality. Long panel data of Swedish individuals is used to estimate the observed trend in income‐related health inequality, measured by the concentration index (CI). A decomposition procedure based on a fixed effects model is used to clarify the channels by which population aging affects health inequality. Based on current income rankings, we find that conventional unstandardized and age–gender‐standardized CIs increase over time. This trend in CIs is, however, found to remain stable when people are instead ranked according to lifetime (mean) income. Decomposition analyses show that two channels are responsible for the upward trend in unstandardized CIs – retired people dropped in relative income ranking and the coefficient of variation of health increases as the population ages. Copyright © 2009 John Wiley & Sons, Ltd.     

Whose health is affected by income inequality? A multilevel interaction analysis of contemporaneous and lagged effects of state income inequality on individual self-rated health in the United States

The empirical relationship between income inequality and health has been much debated and discussed. Recent reviews suggest that the current evidence is mixed, with the relationship between state income inequality and health in the United States (US) being perhaps the most robust. In this paper, we examine the multilevel interactions between state income inequality, individual poor self-rated health, and a range of individual demographic and socioeconomic markers in the US. We use the pooled data from the 1995 and 1997 Current Population Surveys, and the data on state income inequality (represented using Gini coefficient) from the 1990, 1980, and 1970 US Censuses. Utilizing a cross-sectional multilevel design of 201,221 adults nested within 50 US states we calibrated two-level binomial hierarchical mixed models (with states specified as a random effect). Our analyses suggest that for a 0.05 change in the state income inequality, the odds ratio (OR) of reporting poor health was 1.30 (95% CI: 1.17-1.45) in a conditional model that included individual age, sex, race, marital status, education, income, and health insurance coverage as well as state median income. With few exceptions, we did not find strong statistical support for differential effects of state income inequality across different population groups. For instance, the relationship between state income inequality and poor health was steeper for whites compared to blacks (OR=1.34; 95% CI: 1.20-1.48) and for individuals with incomes greater than $75,000 compared to less affluent individuals (OR=1.65; 95% CI: 1.26-2.15). Our findings, however, primarily suggests an overall (as opposed to differential) contextual effect of state income inequality on individual self-rated poor health. To the extent that contemporaneous state income inequality differentially affects population sub-groups, our analyses suggest that the adverse impact of inequality is somewhat stronger for the relatively advantaged socioeconomic groups. This pattern was found to be consistent regardless of whether we consider contemporaneous or lagged effects of state income inequality on health. At the same time, the contemporaneous main effect of state income inequality remained statistically significant even when conditioned for past levels of income inequality and median income of states.     

Is income relevant for health expenditure and economic growth nexus?

This paper examines the relationship between health expenditure and economic growth using panel data consisting low and high-income countries. Using dynamic panel data methodology, we analyze twenty five high-income and nineteen low-income economies for the periods of 1995–2012 and 1997–2009, respectively. We find reciprocal relationship between health expenditure and economic growth in the short run and one-way causality from economic growth to public health expenditure in the long-run. In high-income countries, there is a two-way causality for both private and public health expenditures in the short-run, while in the long-run there is a one-way causality between economic growth and private health expenditures. The crucial finding of this study is that private health expenditures have negative influence on economic growth while public health expenditures have both negative and statistically significant effect.     

Socioeconomic inequality in infant mortality in Iran and across its provinces

OBJECTIVE: To measure the socioeconomic inequality in infant mortality in Iran (the Islamic Republic of Iran). METHODS: We analysed data from the provincially representative Demographic and Health Survey, which was done in Iran in 2000. We used a dichotomous hierarchical ordered probit model to develop an indicator of socioeconomic status of households. We assessed the inequality in infant mortality by using the odds ratio of infant mortality between the lowest and highest socioeconomic quintiles at both the provincial and national levels, and the concentration index, an inequality measure based on the entire socioeconomic distribution. RESULTS: We found a decreasing trend in the infant mortality rate in relation to socioeconomic quintiles. The poorest to richest odds ratio was 2.34 (95% CI = 1.78-3.09). The concentration index of infant mortality in Iran was -0.1789 (95% CI = -0.2193--0.1386). Furthermore, the inequality of infant mortality between the lowest and highest quintiles was significant and favoured the better-off in most of the provinces. However, this inequality varied between provinces. CONCLUSION: Socioeconomic inequality in infant mortality favours the better-off in the country as a whole and in most of its provinces, but the degree of this inequality varies between the provinces. As well as its national average, it is important to consider the provincial distribution of this indicator of population health.     

The contribution of smoking and obesity to income-related inequalities in health in England

Reducing avoidable inequalities in health is a priority in many health care systems, including the NHS in Great Britain. Evidence suggests that lifestyle factors may play a role in explaining socioeconomic inequalities in health. In this paper we measure the contribution of smoking and obesity to income-related inequality in health. We use the corrected concentration index to measure inequality across time and areas of England, and decomposition methods to quantify directly the contribution of smoking and obesity to income-related inequality. Instrumental variables regression is used to test the endogeneity of smoking and obesity. We use data from nine rounds of the Health Survey for England (1998–2006). The results show that there are significant income-related health inequalities in England, that the extent of the inequality varies by area, and that in some areas it has increased over time. Nationally, smoking and obesity make a significant but modest contribution to income-related inequality in health (2.3% and 1.2%, respectively). Despite the reduction in smoking prevalence, the contribution of smoking has slightly increased over time, due to its increasing concentration among the poor and its negative effect on health. While the prevalence of obesity is increasing, it is more equally distributed across society. The prevalence of these problems varies between areas, and so does the contribution they make to income-related inequalities in health.     

Trends in income-related health inequalities in self-assessed health in Korea, 1998–2011

This study assesses income-related health inequalities in self-assessed health (SAH) and its trend from 1998 to 2011 in Korea that covers important time periods of financial crisis and post-crisis. Data came from the Korean National Health and Nutrition Examination Survey from 1998 to 2011. A population-representative sample aged 46 years and older was analysed. SAH was used as an indicator of health status, with household equivalence income as a proxy for socio-economic position. Age-adjusted prevalence rates of SAH were analysed to estimate both absolute and relative measures of health inequalities and the trend over time by the relative index of inequality (RII) and the slope index of inequality (SII). Results indicated that the highest level of health inequalities was found among men aged 46–59 years, especially in 2001 and 2005. For men, there was no clear, consistent pattern of increase or decrease in the trend over time. On the other hand, increasing trends in the RII and SII were found for women, except for women aged 46–59 years who reported a decreasing trend in the SII. Trends in health inequalities over time were influenced by economic crisis, demonstrating the need for macro-level economic policies as well as health policies addressing health gaps.     

Growing old before growing rich: inequality in health service utilization among the mid-aged and elderly in Gansu and Zhejiang Provinces, China

ABSTRACT: BACKGROUND: China's recent growth in income has been unequally distributed, resulting in an unusually rapid retreat from relative income equality, which has impacted negatively on health services access. There exists a significant gap between health care utilization in rural and urban areas and inequality in health care access due to differences in socioeconomic status is increasing. We investigate inequality in service utilization among the mid-aged and elderly, with a special attention of health insurance. METHODS: This paper measures the income-related inequality and horizontal inequity in inpatient and outpatient health care utilization among the mid-aged and elderly in two provinces of China. The data for this study come from the pilot survey of the China Health and Retirement Longitudinal Study in Gansu and Zhejiang. Concentration Index (CI) and its decomposition approach were deployed to reflect inequality degree and explore the source of these inequalities. RESULTS: There is a pro-rich inequality in the probability of receiving health service utilization in Gansu (CI outpatient = 0.067; CI inpatient = 0.011) and outpatient for Zhejiang (CI = 0.016), but a pro-poor inequality in inpatient utilization in Zhejiang (CI = -0.090). All the Horizontal Inequity Indices (HI) are positive. Income was the dominant factor in health care utilization for out-patient in Gansu (40.3 percent) and Zhejiang (55.5 percent). The non-need factors' contribution to inequity in Gansu and Zhejiang outpatient care had the same pattern across the two provinces, with the factors evenly split between pro-rich and pro-poor biases. The insurance schemes were strongly pro-rich, except New Cooperative Medical Scheme (NCMS) in Zhejiang. CONCLUSIONS: For the middle-aged and elderly, there is a strong pro-rich inequality of health care utilization in both provinces. Income was the most important factor in outpatient care in both provinces, but access to inpatient care was driven by a mix of income, need and non-need factors that significantly differed across and within the two provinces. These differences were the result of different levels of health care provision, different out-of-pocket expenses for health care and different access to and coverage of health insurance for rural and urban families. To address health care utilization inequality, China will need to reduce the unequal distribution of income and expand the coverage of its health insurance schemes.