Inequalities in self-reported health: validation of a new approach to measurement

This paper assesses the internal validity of using the McMaster 'Health Utility Index Mark III' (HUI) to scale the responses on the typical self-assessed health (SAH) question, "how do you rate your health status in general?" It compares alternative procedures to impose cardinality on the ordinal responses. These include OLS, ordered probit and interval regression approaches. The cardinal measures of health are used to compute and to decompose concentration indices for income-related inequality in health. These results are validated by comparison with the individual variation in the 'benchmark' HUI responses obtained from the Canadian 'National Population Health Survey 1994-1995'. The interval regression approach, which exploits a mapping from the empirical distribution function (EDF) of HUI into SAH, outperforms the other approaches. In addition, we show how the method can be extended to allow for differences in SAH thresholds across different groups of people and to measuring and decomposing 'pure' health inequality.     

Income-related health inequality in Canada

This study uses data from the 1994 National Population Health Survey and applies the methods developed by Wagstaff and van Doorslaer (1994, measuring inequalities in health in the presence of multiple-category morbidity indicators. Health Economics 3, 281-291) to measure the degree of income-related inequality in self-reported health in Canada by means of concentration indices. It finds that significant inequalities in self-reported ill-health exist and favour the higher income groups--the higher the level of income, the better the level of self-assessed health. The analysis also indicates that lower income individuals are somewhat more likely to report their self-assessed health as poor or less-than-good than higher income groups, at the same level of a more 'objective' health indictor such as the McMaster Health Utility Index. The degree of inequality in 'subjective' health is slightly higher than in 'objective' health, but not significantly different. The degree of inequality in self-assessed health in Canada was found to be significantly higher than that reported by van Doorslaer et al. (1997, income related inequalities in health: some international comparisons, Journal of Health Economics 16, 93-112) for seven European countries, but not significantly different from the health inequality measured for the UK or the US. It also appears as if Canada's health inequality is higher than what would be expected on the basis of its income inequality.     

Measuring health polarization with self-assessed health data

This paper proposes an axiomatic foundation for new measures of polarization that can be applied to ordinal distributions such as self-assessed health (SAH) data. This is an improvement over the existing measures of polarization that can be used only for cardinal variables. The new measures of polarization avoid one difficulty that the related measures for evaluating health inequalities face. Indeed, inequality measures are mean based, and since only cardinal variables have a mean, SAH has to be cardinalized to compute a mean, which can then be used to calculate an inequality measure. In contrast, the new polarization measures are median based and hence do not require to impose cardinal scaling on the categories. After deriving the properties of these new polarization measures, we provide an empirical illustration using data from the British Household Panel Survey that demonstrates that SAH polarization is also a relevant question on empirical grounds, and that the polarization measures are adequate to evaluate polarization phenomena whereas inequality measures are not adequate in these cases.     

Health inequality measurement in Korea using EuroQol-5 Dimension valuation weights]

OBJECTIVES: Despite various government initiatives, including the expansion of national health insurance coverage, health inequality has been a key health policy issue in South Korea during the past decade. This study describes and compares the extent of the total health inequality and the income-related health inequality over time among Korean adults. METHODS: This study employs the 1998, 2001 and 2005 Korean National Health and Nutrition Examination Surveys (KNHANESs). The self-assessed health (SAH) ordinal responses, measured on a five-point scale, rescaled to cardinal values to measure the health inequalities with using interval regression. The boundaries of each threshold for the interval regression analysis were obtained from the empirical distribution of the EuroQol-5 Dimension (EQ-5D) valuation weights estimated from the 2005 KNHANES. The final model predicting the individuals' health status included age, gender, educational attainment, occupation, income, and the regional prosperity index. The concentration index was used to measure and analyze the health inequality. RESULTS: The KNHANES data showed an unequal distribution of the total health inequality in favor of the higher income groups, and this is getting worse over time (0.0327 in 1998, 0.0393 in 2001 and 0.0924 in 2005). The income-related health inequality in 2005 was 0.0278, indicating that 30.1% of the total health inequality can be attributed to income. CONCLUSIONS: The findings indicate there are health inequalities across the sociodemographic and income groups despite the recent government's efforts. Further research is warranted to investigate what potential policy actions are necessary to decrease the health inequality in Korea.     

Income inequality,perceived happiness,and self-rated health: Evidence from nationwide surveys in Japan

In this study, we examined how regional inequality is associated with perceived happiness and self-rated health at an individual level by using micro-data from nationwide surveys in Japan. We estimated the bivariate ordered probit models to explore the associations between regional inequality and two subjective outcomes, and evaluated effect modification to their sensitivities to regional inequality using the categories of key individual attributes. We found that individuals who live in areas of high inequality tend to report themselves as both unhappy and unhealthy, even after controlling for various individual and regional characteristics and taking into account the correlation between the two subjective outcomes. Gender, age, educational attainment, income, occupational status, and political views modify the associations of regional inequality with the subjective assessments of happiness and health. Notably, those with an unstable occupational status are most affected by inequality when assessing both perceived happiness and health.     

Does inequality in self-assessed health predict inequality in survival by income? Evidence from Swedish data

This paper empirically addresses two questions using a large, individual-level Swedish data set which links mortality data to health survey data. The first question is whether there is an effect of an individual's self-assessed health (SAH) on his subsequent survival probability and if this effect differs by socioeconomic factors. Our results indicate that the effect of SAH on mortality risk declines with age-probably because of adjustment towards 'milder' overall health evaluations at higher ages-but does not seem to differ by indicators of socioeconomic status (SES) like income or education. This finding suggests that there is no systematic adjustment of SAH by SES and therefore that any measured income-related inequality in SAH is unlikely to be biased by reporting error. The second question is: how much of the income-related inequality in mortality can be explained by income-related inequality in SAH? Using a decomposition method, we find that inequality in SAH accounts for only about 10% of mortality inequality if interactions are not allowed for, but its contribution is increased to about 28% if account is taken of the reporting tendencies by age. In other words, omitting the interaction between age and SAH leads to a substantial underestimation of the partial contribution of SAH inequality by income. These results suggest that the often observed inequalities in SAH by income do have predictive power for the-less often observed-inequalities in survival by income.     

Equity in the finance of health care: some further international comparisons.

This paper presents further international comparisons of progressivity of health care financing systems. The paper builds on the work of Wagstaff et al. [Wagstaff, A., van Doorslaer E., et al., 1992. Equity in the finance of health care: some international comparisons, Journal of Health Economics 11, pp. 361-387] but extends it in a number of directions: we modify the methodology used there and achieve a higher degree of cross-country comparability in variable definitions; we update and extend the cross-section of countries; and we present evidence on trends in financing mixes and progressivity.     

Ordered multinomial regression for genetic association analysis of ordinal phenotypes at Biobank scale

Logistic regression is the primary analysis tool for binary traits in genome-wide association studies (GWAS). Multinomial regression extends logistic regression to multiple categories. However, many phenotypes more naturally take ordered, discrete values. Examples include (a) subtypes defined from multiple sources of clinical information and (b) derived phenotypes generated by specific phenotyping algorithms for electronic health records (EHR). GWAS of ordinal traits have been problematic. Dichotomizing can lead to a range of arbitrary cutoff values, generating inconsistent, hard to interpret results. Using multinomial regression ignores trait value hierarchy and potentially loses power. Treating ordinal data as quantitative can lead to misleading inference. To address these issues, we analyze ordinal traits with an ordered, multinomial model. This approach increases power and leads to more interpretable results. We derive efficient algorithms for computing test statistics, making ordinal trait GWAS computationally practical for Biobank scale data. Our method is available as a Julia package OrdinalGWAS.jl. Application to a COPDGene study confirms previously found signals based on binary case–control status, but with more significance. Additionally, we demonstrate the capability of our package to run on UK Biobank data by analyzing hypertension as an ordinal trait.     

What is the relationship between income inequality and health? Evidence from the BHPS

Income inequality hypotheses propose that income differentials and/or income distributions have a detrimental effect on health. This previously well accepted relationship between inequality and health has recently come under scrutiny; some claim that it is a statistical artefact, arguing that aggregate level data are not sophisticated enough to adequately test for (and discriminate between) their existence. Supporters argue that it is a question of estimating the relationship using, amongst other things, an appropriate geographical scale. This paper adds to the debate by estimating the relationship between income inequality and health using individual panel data, exploring the relationship at the regional as well as the national level, while attempting to discriminate between the competing hypotheses. Pooled, random and fixed effects ordered probit models are exploited to estimate the relationship between self-reported health and household income, income inequality and relative income. While the estimating regressions find support for the absolute income hypothesis, there is no support for the income inequality hypothesis or relative income hypothesis, and as such we argue that there is limited evidence of an effect of income inequality on health within Britain.     

ON THE CARDINAL MEASUREMENT OF HEALTH INEQUALITY WHEN ONLY ORDINAL INFORMATION IS AVAILABLE ON INDIVIDUAL HEALTH STATUS

This paper suggests new indices of health inequality which may be used when only ordinal information is available on individual health status. We borrow ideas from the literature on the measurement of occupational or residential segregation and show that indices of ordinal segregation which have been recently proposed may be also applied to the measurement of health inequality. We also prove that these indices satisfy four axioms introduced to measure inequality with ordered response health data so that the new indices presented in this paper are consistent with the inequality ordering proposed by Allison and Foster. We also suggest an extension of the family of indices proposed by Abul Naga and Yalcin. Copyright © 2011 John Wiley & Sons, Ltd.     

Quasi-Likelihood Analysis of Patient Satisfaction with Medical Care

In health services research studies, a score for satisfaction with care is often determined for a patient by summing several items, each measured on a Likert scale with ordered response options indicating satisfaction with some aspect of medical care (e.g., five categories ordered 1-poor to 5-excellent). A common goal is to determine patient and physician level predictors of patient satisfaction using regression analysis. The large number of categories in the ordinal summed response variable may present obstacles to traditional analytic methods for ordinal data such as the proportional odds model for cumulative logits. Further, linear regression is generally known to be inappropriate. Quasi-likelihood methods provide a flexible and tractable alternative modelling procedure. Weak assumptions about the measurement scale may be made by estimating parameters that define a family of link functions. A quasi-likelihood analysis of data from a study of elderly patients' satisfaction with communication with their primary care physician is presented. Although several factors are significantly related to satisfaction, a diagnostic plot based upon cumulative deviances reveals inadequacy of fit for the patients with the lowest observed satisfaction.     

Making health continuous: implications of different methods on the measurement of inequality

In most national surveys, health is measured as a categorical variable. However, in order to be able to calculate socio-economic inequalities in health, a continuous variable is needed. The recently developed interval regression approach was shown to outperform to other approaches like ordered probit. In this research we investigate the impact of using different sets of external data to estimate health inequalities: the EQ-index and the Canadian HUI. We found that the concentration index differs, but the income-related health mobility index and its decomposition are highly similar. Copyright (c) 2005 John Wiley & Sons, Ltd.     

Has Income-related Inequity in Health Care Utilization and Expenditures Been Improved? Evidence From the Korean National Health and Nutrition Examination Survey of 2005 and 2010

Objectives

The purpose of this study is to examine and explain the extent of income-related inequity in health care utilization and expenditures to compare the extent in 2005 and 2010 in Korea.

Methods

We employed the concentration indices and the horizontal inequity index proposed by Wagstaff and van Doorslaer based on one- and two-part models. This study was conducted using data from the 2005 and 2010 Korean National Health and Nutrition Examination Survey. We examined health care utilization and expenditures for different types of health care providers, including health centers, physician clinics, hospitals, general hospitals, dental care, and licensed traditional medical practitioners.

Results

The results show the equitable distribution of overall health care utilization with pro-poor tendencies and modest pro-rich inequity in the amount of medical expenditures in 2010. For the decomposition analysis, non-need variables such as income, education, private insurance, and occupational status have contributed considerably to pro-rich inequality in health care over the period between 2005 and 2010.

Conclusions

We found that health care utilization in Korea in 2010 was fairly equitable, but the poor still have some barriers to accessing primary care and continuing to receive medical care.     

Does reporting behaviour bias the measurement of social inequalities in self-rated health in Indonesia? An anchoring vignette analysis

Purpose

Studies on self-rated health outcomes are fraught with problems when individuals’ reporting behaviour is systematically biased by demographic, socio-economic, or cultural factors. Analysing the data drawn from the Indonesia Family Life Survey 2007, this paper aims to investigate the extent of differential health reporting behaviour by demographic and socio-economic status among Indonesians aged 40 and older (\(N = 3735\)).

Methods

Interpersonal heterogeneity in reporting style is identified by asking respondents to rate a number of vignettes that describe varying levels of health status in targeted health domains (mobility, pain, cognition, sleep, depression, and breathing) using the same ordinal response scale that is applied to the self-report health question. A compound hierarchical ordered probit model is fitted to obtain health differences by demographic and socio-economic status. The obtained regression coefficients are then compared to the standard ordered probit model.

Results

We find that Indonesians with more education tend to rate a given health status in each domain more negatively than their less-educated counterparts. Allowing for such differential reporting behaviour results in relatively stronger positive education effects.

Conclusion

There is a need to correct for differential reporting behaviour using vignettes when analysing self-rated health measures in older adults in Indonesia. Unless such an adjustment is made, the salutary effect of education will be underestimated.

     

Adaptation to health states: Sick yet better off?

Healthcare funding decisions in the UK rely on health state valuations of the general public. However, it has been shown that there is disparity between the valuation of the impact of hypothetical conditions on health and the reported health by those experiencing them. Patients' adaptation to health states is among the most common explanations for this discrepancy. Being diagnosed with a disease appears to affect individual perception of health over time so that better subjective health may be reported over a disease trajectory. This paper examines adaptation to health states using a longitudinal dataset. We use four waves of the British Cohort Study (BCS70), which tracks a sample of British individuals since birth in 1970 and contains information on self‐assessed health (SAH), morbidity, and socioeconomic characteristics. We implement a dynamic ordered probit model controlling for health state dependence. Results are supportive of the existence of adaptation: Time since diagnosis has a positive impact on SAH. Moreover, adaptation happens over relatively long durations. We do not find significant results proving different adaptation paths for patients reporting prior better SAH. The analysis by specific conditions generally supports the existence of adaptation, but results are statistically significant only for a subset of conditions.     

城乡居民医疗保险对流动人口的健康促进效用研究

目的 考察城乡居民医疗保险制度对流动人口促健效用。方法 利用2014年和2016年中国劳动力动态调查问卷数据,选取2 016名流动人口作为研究对象,统计方法主要采用Probit模型、OLS回归和倾向得分匹配法(PSM)。结果 Probit模型结果显示,参加城乡居民医疗保险能使流动人口自评健康指标得分提升20.2%(t = - 5.090,OR = 0.993,95%CI: - 0.280～ - 0.124);OLS回归表明流动人口虚弱指数降低3.3%(t = - 4.500,OR = 0.222,95%CI: - 0.046～- 0.018);使用倾向得分匹配法(PSM)纠正变量间的内生性后所得结论依旧稳健。上述结论表明参与城乡居民医疗保险对流动人口具有健康促进作用。结论 重视城乡居民医疗保险对流动人口健康的促进作用,加快城乡居民医疗保险统筹,提升流动人口城乡居民医疗保险参保率,增强流动人口医疗服务可获得性,提高流动人口健康水平。     

Equity and equality in the use of GP services for elderly people: the Spanish case

Objectives

To present new evidence both on the horizontal inequity in the delivery of primary health care and on the factors driving inequalities in the use of GP services for Spanish population aged 50 years and over.

Methods

Cross-sectional study based on the Spanish sample of the Survey of Health, Aging and Retirement in Europe (SHARE) for 2006-07. We use the index proposed by Wagstaff and van Doorslaer (HI_WV) to compute health care inequity. The concentration index measuring income related inequality in health care use is decomposed into the contribution of each determinant.

Results

Our results show the presence of pro-poor inequality in both the access and the frequency of use for GP services, which is mainly explained by unequal distribution of need factors. The contribution of non-need factors to income related inequality is quite higher for the conditional number of GP visits (48.13%) than for the probability of positive use (17.55%). We have also found significant pro-poor inequity in the probability of access to a GP and in the conditional number of visits for elderly people.

Conclusions

The relevance of social determinants of health is confirmed, and hence the need for wide-scoped public policies to reduce health inequalities. At equal levels of need, rich and poor elderly people are not treated equally. As much as appropriateness of care provided is unknown, we cannot conclude that inequity in GP services really favours the lower income individuals in terms of health gains.     

Inequality and polarisation in health systems' responsiveness: a cross-country analysis

The World Health Report 2000 proposed three fundamental goals for health systems encompassing population health, health care finance and health systems responsiveness. The goals incorporate both an efficiency and equity dimension. While inequalities in population health and health care finance have motivated two important strands of research, inequalities in responsiveness have received less attention in health economics. This paper examines inequality and polarisation in responsiveness, bridging this gap in the literature and contributing towards an integrated analysis of health systems performance. It uses data from the World Health Survey to measure and compare inequalities in responsiveness across 25 European countries. In order to respect the inherently ordinal nature of the responsiveness data, median-based measures of inequality and polarisation are employed. The results suggest that, in the face of wide differences in the health systems analysed, there exists large variability in inequality in responsiveness across countries.     

Meeting the health care needs of female crack users: a Canadian example

Canada is an egalitarian society committed to accessible and comprehensive health care. Although there has been a tendency to assume that its various social welfare programs have improved health conditions for lower income citizens, Canada's record in ensuring health equality remains poorer than expected (Humphries and van Doorslaer, 2000; Wasylenki, 2001). The Canadian Health Act stipulates that all residents of Canada are to have access to medically necessary hospital and physician services based on need and not the ability to pay. However, for marginalized groups such as drug users and the homeless, structural barriers to better health remain. This paper examines the health care needs and experiences of 30 women who were heavily involved in the street life of crack and prostitution in Toronto. Through their ready access to local drop-in clinics and nearby hospitals, the women reported generally positive experiences with the health care system. The study concludes that the women experienced many of the health problems that typify homeless, poorly housed and economically marginalized groups. Both positive and negative experiences with the health care system, and structural barriers that hamper its full utilization, are identified.