This study examined (1) the differences heat- and cold-related risks on hospitalization between people eligible and non-eligible for the medical aid system in the national health insurance service system and (2) differences of the heat- and cold-related risk and cost differences by specific subgroups in South Korea. We collected population-based longitudinal cohort data from the National Health Insurance Service-National Health Insurance Database (NHIS-NHID) from 2010 to 2019. The data included all individuals who were eligible for the Korean Medical Aid (MA) system during the study period, and we used their data on hospitalization through the emergency department. As a control group, we collected age-sex-residential address matched individuals who were not eligible for the MA system. Results: During the study period, 509480 hospital admissions to the emergency department (ED) were recorded among 1466176 beneficiaries eligible for MA. Among MA beneficiaries, the estimated risk for ED admission attributable to heat was 1.19 (95% CI: 1.14-1.24) and the risk attributable to cold temperature was 1.52 (95% CI: 1.43-1.61), which were both higher than those of the control groups incorporating matched beneficiaries who were not eligible for MA. For both heat and cold, the difference between MA and non-MA was prominent in non-elderly populations, males, people with disabilities, and admissions with mental and cardiovascular diseases. This study revealed the hypothesis that the differences in heat and cold-related risks in the socially marginalized population existed and suggested the disparities might be also disproportionate by socioeconomic and demographic statuses. 

- Author (Pusan National University): Whanhee Lee (School of Biomedical Convergence Engineering)

- Title of original paper: Double disparities of the excess risks and costs of extreme temperatures on hospitalization between Medical Aid and non-Medical Aid populations in South Korea

- Journal: International Journal of Epidemiology

- Web link: https://academic.oup.com/ije/article/54/2/dyaf027/8098158 

- Contact email: whanhee.lee@pusan.ac.kr