Full Title: Adult Mortality in India: the Health–Wealth Nexus
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Full Title: Adult Mortality in India: The Health–Wealth Nexus Debasis Barik Associate Fellow National Council of Applied Economic Research [email protected] Sonalde Desai Professor of Sociology, University of Maryland College Park And Senior Fellow, National Council of Applied Economic Research [email protected] Reeve Vanneman Professor of Sociology, University of Maryland College Park [email protected] February 26, 2016 India Human Development Survey was funded by grants R01HD041455 and R01HD061048 from the US National Institutes of Health and a supplementary grant from the Ford Foundation. Data analysis was the funded by the UK government as part of its Knowledge Partnership Programme (KPP). PAA 2016 | Session 58 Adult Mortality in India: The Health–Wealth Nexus Debasis Barik, Sonalde Desai, Reeve Vanneman Abstract Research on wealth and adult mortality is often stymied by the reciprocity of this relationship. While financial resources increase access to healthcare and nutrition and reduce mortality, sickness also reduces labor force participation, thereby reducing income. Without longitudinal data, it is difficult to study the linkage between economic status and mortality. Using data from a national sample of 133,379 comprising Indian adults aged 15 years and above, this paper examines their likelihood of death between wave 1 of the India Human Development Survey (IHDS), conducted in 2004-05 and wave 2, conducted in 2011- 12. The results show that mortality between the two waves is strongly linked to the economic status of the household at wave 1. Household wealth is positively associated with the manifestation of hypertension, diabetes and cardiac conditions, but wealth also reduces the likelihood of death conditional on having these diseases. Keywords: Adult Mortality, health, morbidity, hypertension, wealth, SES, India, Asia 2 | P a g e PAA 2016 | Session 58 INTRODUCTION A strong relationship between economic deprivation and ill-health was first scientifically documented by René Villermé, who compared mortality rates and poverty across the arrondissements of Paris in the 1820s, though references to the relationship can be found even in ancient Greek and Chinese texts (Deaton 2002). It is well recognized in the literature that income is associated with declining mortality and rising longevity in cross- national comparisons (Preston 1975) as well as between the rich and the poor in the same society (Kitagawa 1973). In spite of this observed correlation, empirical research on the causal linkages between health and economic status faces several challenges, as listed below: (a) Although poverty may lead to poor health and higher mortality, poor health may also lead to a decline in the economic status since illness may result in labor force withdrawal or higher health- related expenditure. In this case, poverty may be the result rather than the determinant of ill- health and mortality (Smith 1999); (b) Rising incomes may lead to greater consumption of processed foods and a more sedentary lifestyle, resulting in poor health (Razzell and Spence 2006); and, (c) The protective effect of income on health may depend on the nature of health systems in contexts where state-funded public health systems are effective in reducing income inequalities in health (Chen, Yang and Liu 2010). In this paper, we examine the relationship between household economic status and adult mortality in India, taking into account the caveats mentioned above. The India Human Development Survey conducted in 2004-05 and again in 2011-12 allows us to link household economic status and health conditions at one point in time with subsequent mortality for 133,379 adults aged 15 years and above. Using these prospective data, we address the following three questions: 3 | P a g e PAA 2016 | Session 58 1. Is household economic status associated with the probability of adult death in the subsequent seven years? 2. Are individuals from higher economic strata more likely to suffer from chronic conditions that may reduce the probability of their survival? 3. Is the relationship between chronic health conditions and mortality similar for the rich and the poor? Health and wealth: correlation and causation It has long been recognized that poverty is associated with ill-health (Deaton 2002). In England and Wales, the systematic documentation of mortality by occupational class began as early as 1851, with the publication of Decennial Supplements to the Annual Report of the Registrar General. Social class differentials in mortality became the focus of systematic study in the United States only in the latter half of the twentieth century, with the publication of Kitagawa and Hauser’s path-breaking study of demographic and socio- economic mortality differentials. This study was based on the 1960 Census matched to death certificates filed in May–August of the same year (Hummer, Rogers and Eberstein 1998; Kitagawa 1973). Although there exists ample literature on the nexus between socio-economic status and health and mortality, research on this issue in an Asian context gained prominence only in the 1990s (Chen et al. 2010; Liang et al. 2000; Liu, Hermalin and Chuang 1998; Zimmer 2008; Zimmer and Amornsirisomboon 2001; Zimmer, Kaneda and Spess 2007a; Zimmer et al. 2007b). In spite of the considerable body of evidence showing this correlation, the direction of causation has not been clearly established. Although medical practitioners and public health researchers tend to emphasize the impact of economic status on health and mortality, economists tend to argue that poor health restricts an individual’s capacity to earn income 4 | P a g e PAA 2016 | Session 58 and accumulate assets by limiting work or by raising medical expenses. In his pioneering article titled “Healthy Bodies and Thick Wallet”, James P. Smith (1999) concluded that the causal direction of the social health gradient is not uniform across the life-cycle. During the pre-retirement period, health affects income, whereas for older individuals, income affects health. However, it seems likely that the nature of the relationship may be different for societies where extended households prevail, resulting in income pooling between different members of the household, and where sick members may co-reside with other family members in order to gain financial and logistical help. Thus, an examination of the relationship between wealth and health, particularly mortality, in a low to middle income country like India may offer interesting insights. The challenge of rising prosperity Higher economic status improves access to food, living conditions and access to medical care but also poses several challenges, particularly in a transition society like India. Higher income individuals typically tend to engage in non-manual work, reducing physical activity, which, in turn, reduces caloric needs; but their food intake rises due to growing income. Moreover, greater incomes may lead to what individuals consider as “superior foods”, which in the case of India, include refined cereals, and the consumption of rice and wheat instead of small millets as also the higher consumption of fats, all of which may be linked to rising rates of diabetes rather than improving health (Mohan et al. 2010). This is a distinctly different scenario from that prevalent in industrial societies where the proportion of individuals involved in manual labor is smaller and the consumption of organic and unrefined food is more expensive than mass-produced processed but less healthy foods. Consequently, obesity is associated with poverty rather than wealth. This has been 5 | P a g e PAA 2016 | Session 58 particularly documented in the United States where the rates of obesity and of associated chronic disease are higher among the poor rather than the rich (Levine 2011). In contrast, India is still at a developmental stage where the poor tend to be undernourished while obesity among the rich is rising, consequently creating what has come to be known as a the ‘dual burden of malnutrition’ (Ramachandran 2016). Part of this burden may be attributable to a greater consumption of refined cereals (Mohan et al. 2010), as well as the consumption of restaurant food and declining physical activity levels among the rich urban residents (National Sample Survey Organisation 2012). Along with rising obesity, the prevalence of cardio-vascular diseases and diabetes has also been rising in India, a topic to which we return below. This brief review suggests that higher incomes may not always lead to better health outcomes, particularly in a country that is undergoing substantial transitions in lifestyles. Factors mediating the wealth–mortality nexus One would expect higher income-based inequalities in health under the following two conditions: (1) Where the proportion of deaths due to communicable diseases is lower; and, (2) Where social safety nets and public health systems are more effective. In societies characterized by the prevalence of contagious diseases, both high and low-income individuals may be equally likely to experience high levels of morbidity. Research on maternal education and child health documents a far weaker relationship between maternal education (and the associated socio-economic advantages) and child health in Sub-Saharan Africa than in other settings (Desai and Alva 1998). It is also possible that in countries where public health systems are strong, even poor individuals may be able to access healthcare, thereby leading to a reduction in income inequalities in health outcomes (Mackenbach 2002; Mackenbach et al. 2015). 6 | P a g e PAA 2016 | Session 58 India stands at the cusp of the epidemiological transition. Although communicable diseases remain dominant in the country, the prevalence of non-communicable diseases (NCDs) is rising. Cardiovascular diseases, strokes, diabetes, and cancer are the four leading NCDs in India (Upadhyay 2012). India has the highest number of people with diabetes in the world (Ghaffar, Reddy and Singhi 2004) and this burden has been rising over time (Kaveeshwar and Cornwall 2014), which is why it is often referred to as the ‘diabetic capital of the world’ (IDF 2009).