Cold spells and mortality among people with disabilities: effect modification by cold spell duration, disability type, and severity in Korea

We aimed to evaluate the mortality risk associated with duration of exposure to cold spells in people with disabilities (PWDs) by disability type and severity. Mortality data for PWDs and non-disabled individuals (NDs) were sourced from the Korean National Health Insurance Service and Ministry of Data and Statistics, respectively, between October and April from 2002 to 2021. Cold spells were defined as a decrease of ≥ 15℃ compared to the previous day with a daily minimum temperature ≤ 3℃ or a daily minimum temperature ≤ − 15℃ by the Korea Meteorological Administration. Mortality risks were estimated using a case time series with a distributed lag non-linear model. Individuals with severe disabilities had a significantly higher risk of accidental mortality during ≥ 2 days of cold spells than on non-extreme cold days (relative risk [95% confidence interval]: 1.726 [1.034, 2.880]). Those with speech, intellectual, mental, and respiratory disabilities had an increased all-cause mortality risk during prolonged events. Specific risks emerged on the first day: visual disabilities (accidental and cardiovascular cause); mental disabilities (cardiovascular cause); hearing disabilities (respiratory cause). Prolonged events are associated with increased mortality risks among severe PWDs, with variations by disability type and severity. Tailored interventions and policies are essential to protect these vulnerable populations during extreme cold.