A 10-year trend in income disparity of cardiovascular health among older adults in South Korea

Abstract

Objectives: Although cardiovascular disease (CVD) risk has lessened in Korea, it is unclear whether older adults in all socioeconomic strata have benefited equally. This study explored trends in income disparities in CVD risk among older adults in Korea.

Methods: This was a secondary analysis of Korean National Health and Nutrition Examination Survey data (2008-2017), targeting 14,836 older adults (≥65 years). Socioeconomic position, defined as income and use of welfare benefits, was the primary indicator. The outcome was binary for predicted CVD risk (<90th vs. ≥ 90th). The Slope Index of Inequality (SII) and Relative Index of Inequality (RII) were used to assess trends in disparities.

Results: The percentage of older adults with a predicted CVD risk of 90% or more declined over time, but this was due to a decrease among the more affluent. Disparities have persisted since 2012, with a worsening trend seen for Medicaid recipients. We found significant absolute and relative disparities among men over 75 years of age in recent years (SII > 0.19, RII > 7).

Conclusions: These results may inform and improve policies regarding income disparity reduction and cardiovascular health.

Keywords: CVD, cardiovascular disease; Cardiovascular health; GLM, generalized linear model; Income; KCDC, Korean centers for disease control and prevention; KNHANES, Korean national health and nutrition examination survey; KNHI, Korean national health insurance; Korea; MAR, missing at random; OECD, organization for economic cooperation and development; Older adults; RD, risk difference; RII, relative index of inequality; RR, relative risk; SEP, socioeconomic position; SII, slope index of inequality; Trends.

Fig. 1

Trends in slope index of inequality over time by age group and gender.

Fig. 2

Trends in relative index of inequality over time by age group and gender.