Caste differences in hypertension among women in India: diminishing health returns to socioeconomic status for lower caste groups.
Original author: Uddin, J., Acharya, S., Valles, J. et al. (2020) (DOI: 10.1007/s40615-020-00723-9)
Jr. Economist intern
December 20, 2022
The caste system is a relatively rigid system of social hierarchy in India. Caste membership defines one’s access to resources and life opportunities. A growing body of research suggests that lower caste groups have an excess burden of morbidity and mortality in India. Hypertension is a serious risk factor for many non-communicable diseases and has become a major global public health concern.
They have used de-identified data from the National Family Health Survey (NFHS) 2015–2016, India. The NFHS is a nationally representative population-based household survey. The NFHS follows a two-stage probability sampling strategy. The first stage of the sampling strategy includes the selection of villages as the primary sampling unit (PSU) in rural areas and census enumeration blocks (CEB) in urban areas. In the second stage, using systematic random sampling, 22 households were selected from each PSU and CEB, resulting in a total of 628,900 households, of which 601,509 households were finally selected for interviews. In the selected households, 723,875 women aged 15–49 years were found to be eligible for an interview using the women’s questionnaire. Of the eligible women respondents, 699,686 took part in the interviews with a response rate of 97%. After deleting cases with missing information on any of the variables included in the analysis, the analytic sample consisted of 648,064 women aged 15–49 years. The survey used standardized protocols and field-friendly technologies to examine blood pressure (BP). Using the Omron blood pressure monitor, BP was measured three times at five-minute intervals. Finally, hypertension was defined as having an average systolic BP of ≥ 140 mmHg, and/or diastolic BP ≥ 90 mmHg, and/or self-reported use of any antihypertensive medication.
Social caste was based on the respondent’s self-reports of whether they belong to one of the following categories: scheduled caste, scheduled tribe, other backward castes, and other castes. SES indicators include education and the wealth index. The analysis controls for several sociodemographic factors, health behaviors, and health conditions were analyzed.
The analysis included 648,064 Indian women aged 15– 49 years. They used logistic regression analysis to regress a binary outcome of hypertension on the caste categories controlling the covariates.
Results & discussion
The prevalence of hypertension was highest in the non-caste (13.34%) group followed by the upper caste (12.70%) and scheduled tribe (11.33%). Other backward classes (10.47%) and scheduled caste (10.45%) categories had a similarly low level of hypertension prevalence. The study found that compared to the upper caste, both scheduled tribe and non-caste women had higher odds of hypertension. However, other backward-class women had lower odds of hypertension. Examining the SES indicators in model 2, they found that increasing education was associated with decreased odds of hypertension.
This study evaluated the caste differences associated with hypertension in India using a nationally representative data set. The analysis revealed population-level caste differences in the prevalence of hypertension and the extent to which two important SES indicators, education, and wealth, condition the caste differences in hypertension among reproductive-age group women. The unique contribution of this study is highlighting caste membership, as an important factor for social stratification in health, which also intersects in complex ways with SES in patterning the population-level disparities associated with hypertension in India.
Impact of research:
These findings provide evidence of differential returns to SES and have implications in understanding the causes of SES patterning in health among the disadvantaged caste groups in India.