Effects of Socioeconomic Status on Alzheimer Disease Mortality in Taiwan

Objective: The combined effects of individual and neighborhood socioeconomic status (SES) on survival rates of patients with Alzheimer's disease (AD) remain unclear. Design: Retrospective cohort study. Setting: National Health Insurance Bureau of Taiwan data (2003-2012). Participants: Patients with AD. Measurements: The authors aimed to analyze the effects of neighborhood and individual SES on the 5-year survival rates of patients with AD. The author defined individual and neighborhood SES based on income-related insurance payment amounts and residence in advantaged versus disadvantaged areas and compared survival rates using the Cox proportional hazards model after adjusting for risk factors. Results: A total of 1,754 patients with AD were identified. Each patient was followed for 5 years or censored. The 5-year overall survival rates were worst for those with a low individual SES in a disadvantaged area. After adjustment for sex, age, and comorbidities, patients with a low individual SES living in disadvantaged areas had the worse survival rate than those with a high SES (hazard ratio: 2.19; 95% confidence interval [CI]: 1.53-3.13). In contrast, after the adjustment for characteristics, patients with a high individual SES in disadvantaged areas had a similar mortality rate to those with a high individual SES in advantaged areas (hazard ratio: 0.93; 95% CI: 0.64-1.35). Conclusion: Despite universal health coverage, patients with AD and a low individual SES in disadvantaged areas exhibited the worst survival rate. The socioeconomic survival gradient among patients with AD in Taiwan may result from differences in major attributes of individual and neighborhood SES.