Trajectories of Alzheimer's Disease Prevalence among National Health Insurance and Medical Aid Beneficiaries from 2010 to 2019.

Purpose: Alzheimer's disease (AD) is the leading cause of dementia and is associated with various socioeconomic factors. This study aimed to ascertain the differences in AD prevalence based on healthcare coverage type as a proxy of socioeconomic status in South Korea.

Materials and methods: We examined Health Insurance Review and Assessment Service claims from 2010-2019, identifying AD as the main disease. Crude prevalence rate and age- and sex-standardized prevalence were estimated from healthcare utilization data. Subgroup analysis by age, sex, comorbidities (hypertension, diabetes, and cardiovascular disease), and type of healthcare coverage [Medical Aid (MA) vs. National Health Insurance (NHI)] was performed to estimate the standardized prevalence rate ratio (PRR).

Results: AD prevalence increased 3.9 times from 2010 (175688 cases) to 2019 (680800 cases). In the NHI group, the standardized prevalence increased 2.3-fold (624.4 in 2010 and 1433.2 in 2019), whereas the MA group saw a 2.7-fold increase (1251.0 in 2010 and 3391.9 in 2019). AD was significantly higher in the MA group from 2010 [PRR=2.00, 95% confidence interval (CI) 1.98-2.03] to 2019 (PRR=2.37, 95% CI 2.35-2.38) compared to the NHI group. From 2010 to 2019, a proportion of comorbidities increased in MA and NHI groups. Compared to the NHI group, the MA group showed significantly higher proportion of comorbidities.

Conclusion: In this study, we identified significant differences in AD prevalence between NHI and MA recipients, with a notable increase in the MA group, especially among those under 60 years of age.