Malavika A. Subramanyam

Is economic growth associated with reduction in child undernutrition in India

An analysis of cross-sectional data from repeated household surveys in India, combined with data on economic growth, fails to find strong evidence that recent economic growth in India is associated with a reduction in child undernutrition.

Are self-reports of health and morbidities in developing countries misleading? Evidence from India.

Self-reported measures of poor health and morbidities from developing countries tend to be viewed with considerable skepticism. Examination of the social gradient in self-reported health and morbidity measures provides a useful test of the validity of self-reports of poor health and morbidities. The prevailing view, in part influenced by Amartya Sen, is that socially disadvantaged individuals will fail to perceive and report the presence of illness or health-deficits because an individuals assessment of their health is directly contingent on their social experience. In this study, we tested whether the association between self-reported poor health/morbidities and socioeconomic status (SES) in India follows the expected direction or not. Cross-sectional logistic regression analyses were carried out on a nationally representative population-based sample from the 1998 to 1999 Indian National Family Health Survey (INFHS); and 1995-1996 and 2004 Indian National Sample Survey (INSS). Four binary outcomes were analyzed: any self-reported morbidity; self-reported sickness in the last 15 days; self-reported sickness in the past year; and poor self-rated health. In separate adjusted models, individuals with no education reported higher levels of any self-reported, self-reported sickness in the last 15 days, self-reported sickness in the last year, and poor self-rated health compared to those with most education. Contrary to the prevailing thesis, we find that the use of self-rated ill-health has face validity as assessed via its relationship to SES. A less dismissive and pessimistic view of health data obtained through self-reports seems warranted.

Relative deprivation in income and self-rated health in the United States

Absolute income is robustly associated with health status. Few studies have, however, examined if relative income is independently associated with health. We examined if, over and above the effects of absolute income, individual relative deprivation in income as well as position in the income hierarchy is associated with individual poor health in the U.S. Using three rounds of the Current Population Surveys (CPS), we analyzed the association between self-rated health (1=fair/poor, 0=otherwise) and the Yitzhaki index of relative deprivation in income and percentile position in the income hierarchy across 17 reference groups. Over and above the effects of absolute income, the odds ratio for reporting poor health among individuals in the highest quintile of relative deprivation compared to the lowest quintile ranged between 2.18 and 3.30, depending on the reference groups used. A 10 percentile increase in income position within reference groups was associated with an odds ratio of poor health of 0.89. Relative deprivation appeared to explain between 33 and 94% of the association between individual income and self-rated health. Relative deprivation in income is independently associated with poor health over and above the well established effects of absolute income on health. Relative deprivation may partly explain the association between income inequality and worse population health status.

Association between economic growth and early childhood undernutrition: evidence from 121 Demographic and Health Surveys from 36 low-income and middle-income countries

BACKGROUND Economic growth is widely regarded as a necessary, and often sufficient, condition for the improvement of population health. We aimed to assess whether macroeconomic growth was associated with reductions in early childhood undernutrition in low-income and middle-income countries. METHODS We analysed data from 121 Demographic and Health Surveys from 36 countries done between Jan 1, 1990, and Dec 31, 2011. The sample consisted of nationally representative cross-sectional surveys of children aged 0-35 months, and the outcome variables were stunting, underweight, and wasting. The main independent variable was per-head gross domestic product (GDP) in constant prices and adjusted for purchasing power parity. We used logistic regression models to estimate the association between changes in per-head GDP and changes in child undernutrition outcomes. Models were adjusted for country fixed effects, survey-year fixed effects, clustering, and demographic and socioeconomic covariates for the child, mother, and household. FINDINGS Sample sizes were 462,854 for stunting, 485,152 for underweight, and 459,538 for wasting. Overall, 35·6% (95% CI 35·4-35·9) of young children were stunted (ranging from 8·7% [7·6-9·7] in Jordan to 51·1% [49·1-53·1] in Niger), 22·7% (22·5-22·9) were underweight (ranging from 1·8% [1·3-2·3] in Jordan to 41·7% [41·1-42·3] in India), and 12·8% (12·6-12·9) were wasted (ranging from 1·2% [0·6-1·8] in Peru to 28·8% [27·5-30·0] in Burkina Faso). At the country level, no association was seen between average changes in the prevalence of child undernutrition outcomes and average growth of per-head GDP. In models adjusted only for country and survey-year fixed effects, a 5% increase in per-head GDP was associated with an odds ratio (OR) of 0·993 (95% CI 0·989-0·995) for stunting, 0·986 (0·982-0·990) for underweight, and 0·984 (0·981-0·986) for wasting. ORs after adjustment for the full set of covariates were 0·996 (0·993-1·000) for stunting, 0·989 (0·985-0·992) for underweight, and 0·983 (0·979-0·986) for wasting. These findings were consistent across various subsamples and for alternative variable specifications. Notably, no association was seen between per-head GDP and undernutrition in young children from the poorest household wealth quintile. ORs for the poorest wealth quintile were 0·997 (0·990-1·004) for stunting, 0·999 (0·991-1·008) for underweight, and 0·991 (0·978-1·004) for wasting. INTERPRETATION A quantitatively very small to null association was seen between increases in per-head GDP and reductions in early childhood undernutrition, emphasising the need for direct health investments to improve the nutritional status of children in low-income and middle-income countries. FUNDING None.

Socioeconomic Inequalities in Childhood Undernutrition in India: Analyzing Trends between 1992 and 2005

Background India experienced a rapid economic boom between 1991 and 2007. However, this economic growth has not translated into improved nutritional status among young Indian children. Additionally, no study has assessed the trends in social disparities in childhood undernutrition in the Indian context. We examined the trends in social disparities in underweight and stunting among Indian children aged less than three years using nationally representative data. Methods We analyzed data from the three cross-sectional rounds of National Family Health Survey of India from 1992, 1998 and 2005. The social factors of interest were: household wealth, maternal education, caste, and urban residence. Using multilevel modeling to account for the nested structure and clustering of data, we fit multivariable logistic regression models to quantify the association between the social factors and the binary outcome variables. The final models additionally included age, gender, birth order of child, religion, and age of mother. We analyzed the trend by testing for interaction of the social factor and survey year in a dataset pooled from all three surveys. Results While the overall prevalence rates of undernutrition among Indian children less than three decreased over the 1992–2005 period, social disparities in undernutrition over these 14 years either widened or stayed the same. The absolute rates of undernutrition decreased for everyone regardless of their social status. The disparities by household wealth were greater than the disparities by maternal education. There were no disparities in undernutrition by caste, gender or rural residence. Conclusions There was a steady decrease in the rates of stunting in the 1992–2005 period, while the decline in underweight was greater between 1992 and 1998 than between 1998 and 2005. Social disparities in childhood undernutrition in India either widened or stayed the same during a time of major economic growth. While the advantages of economic growth might be reaching everyone, children from better-off households, with better educated mothers appear to have benefited to a greater extent than less privileged children. The high rates of undernutrition (even among the socially advantaged groups) and the persistent social disparities need to be addressed in an urgent and comprehensive manner.

Social Factors and Leukocyte DNA Methylation of Repetitive Sequences: The Multi-Ethnic Study of Atherosclerosis

Epigenetic changes are a potential mechanism contributing to race/ethnic and socioeconomic disparities in health. However, there is scant evidence of the race/ethnic and socioeconomic patterning of epigenetic marks. We used data from the Multi-Ethnic Study of Atherosclerosis Stress Study (N = 988) to describe age- and gender- independent associations of race/ethnicity and socioeconomic status (SES) with methylation of Alu and LINE-1 repetitive elements in leukocyte DNA. Mean Alu and Line 1 methylation in the full sample were 24% and 81% respectively. In multivariable linear regression models, African-Americans had 0.27% (p<0.01) and Hispanics 0.20% (p<0.05) lower Alu methylation than whites. In contrast, African-Americans had 0.41% (p<0.01) and Hispanics 0.39% (p<0.01) higher LINE-1 methylation than whites. These associations remained after adjustment for SES. In addition, a one standard deviation higher wealth was associated with 0.09% (p<0.01) higher Alu and 0.15% (p<0.01) lower LINE-1 methylation in age- and gender- adjusted models. Additional adjustment for race/ethnicity did not alter this pattern. No associations were observed with income, education or childhood SES. Our findings, from a large community-based sample, suggest that DNA methylation is socially patterned. Future research, including studies of gene-specific methylation, is needed to understand better the opposing associations of Alu and LINE-1 methylation with race/ethnicity and wealth as well as the extent to which small methylation changes in these sequences may influence disparities in health.

Socioeconomic status, John Henryism and blood pressure among African-Americans in the Jackson Heart Study.

John Henryism connotes a strong behavioral predisposition to engage in effortful, active coping with difficult social and economic stressors. This behavioral predisposition is measured by the 12 item John Henryism Scale for Active Coping (JHAC). The John Henry hypothesis predicts that the well-known inverse socioeconomic status (SES)-blood pressure association will be stronger among persons who score high rather than low on the JHAC. We tested this hypothesis in a large African American cohort using baseline data from the Jackson Heart Study. Unlike previous studies, we used multiple indicators of SES: income, education, occupation, childhood SES and cumulative SES. Because the hypothesis is most relevant for adults still in the labor force, we excluded retired participants, yielding a sample size of 3978. Gender-specific Poisson regression models for hypertension adjusting for age, John Henryism, SES, and a John Henryism-SES interaction term, were fit to examine associations. Separate models were fit for each SES indicator. We found some evidence that John Henryism modified the association between income and hypertension in men: low income was associated with higher prevalence of hypertension in men who scored high on John Henryism (prevalence ratio (PR) for low vs. high income tertile 1.12), but with lower hypertension prevalence among men who scored low on John Henryism (PR 0.85, one sided P value for multiplicative interaction <0.05). For women, the association of low income with higher hypertension prevalence was stronger at lower than higher levels of John Henryism (PR 1.27 and 1.06 at low and high levels of John Henryism respectively, P value<0.05). There was no evidence that John Henryism modified the associations of hypertension with other SES indicators in men or women. The modest support of the John Henryism Hypothesis in men only, adds to the literature on this subject, but underscores questions regarding the gender, spatial, socioeconomic and historical contexts in which the hypothesis is valid.

Are socioeconomic disparities in tobacco consumption increasing in India? A repeated cross-sectional multilevel analysis

Objectives India bears a significant portion of the global tobacco burden with high prevalence of tobacco use. This study examines the socioeconomic patterning of tobacco use and identifies the changing gender and socioeconomic dynamics in light of the Cigarette Epidemic Model. Design Secondary analyses of second and third National Family Health Survey (NFHS) data. Setting and participants Data were analysed from 201 219 men and 255 028 women over two survey rounds. Outcomes and methods Outcomes included smoking (cigarettes, bidis and pipes/cigar), chewed tobacco (paan masala, gutkha and others) and dual use, examined by education, wealth, living environment and caste. Standardised prevalence and percentage change were estimated. Pooled multilevel models estimated the effect of socioeconomic covariates on the log odds of tobacco use by gender, along with fixed and random parameters. Findings Among men (2005−2006), gradients in smoking by education (illiterates: 44% vs postgraduates: 15%) and chewing (illiterates: 47% vs postgraduates: 19%) were observed. Inverse gradients were also observed by wealth, living environment and caste. Chewed tobacco use by women showed inverse socioeconomic status (SES) gradients comparing the illiterates (7.4%) versus postgraduates (0.33%), and poorest (17%) versus richest (2%) quintiles. However, proportional increases in smoking were higher among more educated (postgraduates (98%) vs high schooling only (17%)) and chewing among richer (richest quintile (49%) vs poorest quintile (35%)). Among women, higher educated showed larger declines for smoking—90% (postgraduates) versus 12% (illiterates). Younger men (15–24 years) showed increasing tobacco use (smoking: 123% and chewing: 112%). Older women (35–49 years) show higher prevalence of smoking (3.2%) compared to younger women (0.3%). Conclusions Indian tobacco use patterns show significant diversions from the Cigarette Epidemic Model—from gender and socioeconomic perspectives. Separate analysis by type is needed to further understand social determinants of tobacco use in India.

Adult Education and Child Mortality in India : The Influence of Caste, Household Wealth, and Urbanization

Background: Although socioeconomic position is generally found to be related to health, the associations can be different for different measures of socioeconomic position. We examined the association between adult education and child mortality, and the influence of other socioeconomic markers (caste, household wealth, and urbanization) on this association. Methods: Data were drawn from the 1998–1999 Indian National Family Health Survey, conducted in 26 states and comprising 66,367 children age 5 years or under. Adult education, for the head of household and spouse, was categorized into 0, 1–8, and 9 or more years of schooling. We used logistic regression to estimate associations between education and child mortality in analysis adjusted for other socioeconomic markers. Effect modification by caste, household wealth, and urbanization was assessed by fitting an interaction term with education. Results: Compared with those who had no education, 9 or more years of education for the head of household and for the spouse were associated with lower child mortality (odds ratio [OR] = 0.54; 95% confidence interval [CI] = 0.48–0.62 and OR = 0.44; 95% CI = 0.36–0.54, respectively) in analyses adjusted for age, sex, and state of residence. Further adjustments for caste and urbanization attenuated these associations slightly; when adjustments were made for household wealth the associations were attenuated more substantially. Nevertheless, in fully adjusted models, 9 or more years of education for the head of household (OR = 0.81; 95% CI = 0.70–0.93) and the spouse (OR = 0.75; 95% CI = 0.60–0.94) remained associated with lower child mortality. There was no effect modification of this association by caste, household wealth, and urbanization. Conclusion: Adult education has a protective association with child mortality in India. Caste, household wealth, and urbanization do not modify or completely attenuate this association.

Rejoinder: Need for a data-driven discussion on the socioeconomic patterning of cardiovascular health in India

We thank each of the commentators for their responses to our review of the evidence underlying the association of socioeconomic status and cardiovascular health in India. To briefly recap, we conducted a systematic review of studies that reported an association between measures of socioeconomic status (SES) (specifically, education, household income, occupation, household assets/standard of living index, or a composite of two or more measures) and seven cardiovascular disease (CVD) and related risk factors (CVRF; smoking, diet, physical inactivity, hypertension, diabetes, abnormal lipids and obesity), and risk factor-associated CVD-related mortality (ischaemic heart disease (IHD) and stroke) in India. We found that with the exception of smoking, and low fruit and vegetable intake, CVRF were more prevalent among high SES groups in India than the low SES groups (see Figure 1 and Supplementary Table 1 of our review). Regarding risk factor-associated CVD-related mortality, whereas data are available from several studies, only two of these describe the SES patterning of such mortality, and the current evidence seems to support socioeconomic patterning in both directions. In the largest study, the mortality rates appeared to be higher among the lower SES groups for CVD and stroke, whereas the proportion of deaths from CVD and IHD causes was found to be greatest among higher SES groups (see Figure 2 of our review). Based on this review of the published studies, we concluded that for CVRF, with the exception of smoking, there is no evidence to suggest that these risk factors were more prevalent among the poor and that, at this time, the risk-factor burden remains largely concentrated among higher socioeconomic groups. Although we acknowledge that we may have missed some studies that our search criteria should have identified, and new studies will have undoubtedly been published since our review, we are confident that none of the studies suggested by the four commentaries present any data or study that alters our original conclusion. We also concluded, based on the review of the published studies, that there is no evidence to support the claim that any of the outcomes shown in Figure 1 are increasing among the poor. More evidence is required, particularly for mortality, before a definitive conclusion can be reached but there are no new data or studies that are presented in any of the commentaries to alter this claim. In this rejoinder, we clarify certain misattributions that are made in the commentaries with regard to our paper and highlight three considerations that are necessary to ensure an equitable and informed discourse on the cardiovascular health in India.