Longitudinal trends in schizophrenia among older adults: a 12-year analysis of prevalence and healthcare utilization in South Korea.

As populations age worldwide, it is essential to explore the changing landscape of schizophrenia across different age groups. We analyzed cases of schizophrenia reported over a 12-year period (2010-2021) using the Health Insurance Review and Assessment (HIRA) database of South Korea. We explored changes in the prevalence of schizophrenia, physical comorbidity burden, and healthcare utilization by age. The annual disease prevalence and hospitalization patterns were analyzed using linear regression and linear mixed models. Of 420,203 patients diagnosed with schizophrenia, the number and proportion of older adults (aged ≥ 50 years) significantly increased from 82,556 (0.51%) in 2010 to 188,359 (0.89%) in 2021 (p < 0.001), more rapidly than did those of younger adults. The proportion of older adults increased from 37.0% to 54.7% during this period (p < 0.001); by 2021, 44.9% were medical aid beneficiaries. Lengths of psychiatric hospitalization for older adults increased from 230.2 days to 251.8 days (p = 0.023), significantly greater than for younger adults (p < 0.001), and the use of tertiary/general hospitals decreased over time from 15.2% to 9.5% (p < 0.001) while that of hospitals/nursing homes increased from 76.9% to 88.5% (p < 0.001). Older adults consistently showed significantly higher Charlson Comorbidity Index scores (p < 0.001) and longer lengths of non-psychiatric hospitalization (p < 0.001) than younger adults. These findings highlight the distinct healthcare needs and increasing physical health burden of older adults with schizophrenia.