Healthcare burden and clinical outcomes of polypharmacy in older adults: a population-based cohort study in South Korea.

Abstract

Background: Polypharmacy is a prevalent issue in aging societies, with potential health and cost implications. This study evaluated the impact of polypharmacy on hospitalization rates and healthcare expenditure among individuals aged 65 years and older in South Korea.

Methods: We analyzed integrated data from the 2012-2016 Korean National Health and Nutrition Examination Survey alongside administrative claims data from the National Health Insurance Service and Health Insurance Review and Assessment Service. Medical costs were calculated as total annual per capita expenses, encompassing outpatient visit, hospitalization, and drug costs. Key clinical outcomes included hospitalization and mortality. To evaluate the effects of polypharmacy on outpatient visits, medication costs, and total expenditures, we performed a multivariable linear regression analysis. A two-part model was used to estimate hospitalization costs.

Results: The analysis included 3,297 participants. Polypharmacy was significantly associated with higher hospitalization risk (OR, 1.52; 95% CI, 1.28-1.81) and mortality (OR, 3.17; 95% CI, 1.19-8.44). Polypharmacy also corresponded with increased healthcare expenditures, particularly in total, outpatient visit, and medication costs, with the highest associations observed in individuals aged 65-79 and those living alone. Multivariable linear regression revealed a higher annual average total healthcare cost by 872,018 KRW, with outpatient and medication costs by 324,879 KRW and 536,721 KRW, respectively (p < 0.05) for polypharmacy group than the counterparts.

Conclusion: This study demonstrates that polypharmacy among older adults is significantly associated with higher healthcare costs and risks of hospitalization and mortality. Findings suggest that integrated care models, incorporating medication reviews and tailored care plans, alongside community resources to support isolated seniors, may mitigate healthcare costs and improve health outcomes.