Impact of Disability Status on Mortality in Patients with Gastric Cancer: A Nationwide Study Focusing on Regional Disparities

Abstract

Background: Disparities in mortality according to disability status require investment, as individuals with disabilities form the largest subset of the vulnerable population. This study aimed to investigate the association between mortality and disability status in patients with gastric cancer as well as how regional disparities modify this relationship. Methods: Data were obtained from the National Health Insurance claims database in South Korea for the period of 2006-2019. The outcome measures were all-cause 1-year, 5-year, and overall mortality. The main variable of interest was disability status, categorized into "no disability", "mild disability", and "severe disability". A survival analysis based on the Cox proportional hazards model was conducted to analyze the association between mortality and disability status. Subgroup analysis was conducted according to region. Results: Of the 200,566 study participants, 19,297 (9.6%) had mild disabilities, and 3243 (1.6%) had severe disabilities. Patients with mild disabilities had higher 5- and overall mortality risks, and those with severe disabilities had higher 1-year, 5-year, and overall mortality risks than those without disabilities. These tendencies were generally maintained regardless of the region, but the magnitude of the differences in the mortality rates according to disability status was higher in the group residing in non-capital regions than in the group living in the capital city. Conclusion: Disability status was associated with all-cause mortality in patients with gastric cancer. The degree of the differences in mortality rates among those with "no disability", "mild disability", and "severe disability" was augmented in the group residing in non-capital regions.