Measuring health inequalities: implications of choosing different socioeconomic indicators

Abstract

We aimed to verify the association between different socioeconomic indicators and self-rated health in a nationally representative sample of older adults. This cross-sectional study analyzed the baseline data from the Brazilian Longitudinal Study of Aging (ELSI-Brazil), a population-based cohort study of persons aged 50 years or older. Data was collected using a household and an individual questionnaire at participants’ households. Self-rated health was assessed by a global self-rating item. Three socioeconomic indicators were assessed: individual income, per capita household income, and wealth index. Poisson regression models were performed to estimate the prevalence ratio (PR) and 95% confidence intervals (95%CI) of self-rated health and each socioeconomic indicator, adjusting for covariates. In total, 9,390 older adults answered the outcome question. Whilst for the individual income indicator only the richest quintile showed a statistically significant association with the outcome (PR: 0.90; 95%CI: 0.87; 0.93), for the per capita household income, the fourth (PR: 0.95; 95%CI: 0.91; 0.98) and the fifth quintiles (PR: 0.90; 95%CI: 0.86; 0.94) remained associated with the outcome. Regarding the wealth index, only the second quintile was not associated with the outcome, with lower prevalence of poor self-rated health as richer was the quintile, showing a social gradient. The wealth index seems to be a more adequate indicator, as it reflects resources accumulated over the life course.

Perceived healthcare discrimination and well-being among older adults in the United States and Brazil

“…For the ELSI-Brazil, participants were asked, “In general, how would you evaluate your health?” The response options were “very good or excellent” (6.5%), “good” (36.0%), “regular” (45.3%), “bad” (7.8%) or “very bad” (4.3%). In line with numerous prior studies using ELSI data, we dichotomized this variable by collapsing the top two categories (“very good or excellent” and “good”) and the bottom three categories (“regular,” “bad,” and “very bad”) ( Castro et al, 2018 ; Castro, Lima-Costa et al, 2020 ; Castro et al, 2020 , Castro et al, 2020 ; Fagundes, Amaral Júnior, Menegazzo, Hugo, & Giordani, 2022 ; Seixas, 2021 ; Seixas & Freitas, 2021 ).…”

Wealth index association with self-reported oral health between white and non-white older Brazilians

“…These findings suggest possible patterns of inequality, such as the marginal exclusion or “bottom inequality”. This pattern is identified when a given intervention reaches most of the population, but fails to reach a less privileged group, such as the quintile with the lowest socioeconomic level 27 , 37 . This type of inequality is quite prevalent in middle-income countries such as Brazil 37 .…”

“…Other oral health measures included number of remaining teeth, assessed by: “How many teeth do you have?” with responses categorized considering the functional dentition (presence of 20 teeth or more) as follows: 1 to 9 teeth, 10 to 19 teeth, and 20 or more teeth 26 . The number of teeth is considered an important oral health indicator 22 , 26 , 27 .…”

The alcohol harm paradox and tooth loss among Brazilian older adults

“…Two SEP indicators were set as effect modifiers: Household Wealth index (HWI) (British Medical Journal, 2019) and educational attainment. We chose HWI given recent evidence showing that such an indicator seems to present high discriminant validity of absolute inequality in samples of older adults (Amaral Jr et al, 2021; Fagundes et al, 2022). HWI is produced pooling information on the ownership of durable goods – such as car, washing machine, microwave – using principal component analysis.…”