NATIONWIDE POLYPHARMACY TREND AFTER POLICY IMPLEMENTATION DURING COVID-19: SERIAL CROSS-SECTIONAL ANALYSIS
Author(s)
Takehiro Ishida, DrPH1, Yuexiang Ji, BSc, MSc candidate2, Satoshi Yamaguchi, MSc2, Amy Crawley, BA candidate2, Ayaka Mukuta, BA candidate2, Shu Sasaki, BSN candidate2, Suzuho Matsuda, BA candidate2, SHIORI TOSHIMITSU, BA candidate2, Tomoya Ookado, MBA2, Yui Higa, BA candidate2.
1Teikyo University Graduate School of Public Health, Tokyo, Japan, 2Glocal Innovator & Future Talent Society, Tokyo, Japan.
1Teikyo University Graduate School of Public Health, Tokyo, Japan, 2Glocal Innovator & Future Talent Society, Tokyo, Japan.
OBJECTIVES: Polypharmacy is a serious global health issue, particularly impacting older adults, and is reported to contribute to low medication adherence, resulting in surplus medications. In Japan, outcome-based incentives of 400 JPY (USD 2.5) to reduce duplicate prescriptions were introduced in April 2022. This study analyzed nationwide polypharmacy trends and evaluated the impact of the policy during the COVID-19 pandemic in Japan.
METHODS: A serial cross-sectional study was conducted using NDB Open Data, an aggregated national reimbursement claims database published by the Ministry of Health, Labour and Welfare. Polypharmacy was defined as the use of ≥7 concurrent medications for >2 weeks, based on criteria adopted for Japanese outcome-based reimbursement incentives. The outcome, polypharmacy proportion (PP), was defined as the proportion of polypharmacy prescriptions among all annual prescriptions. Data from FY2020 to FY2023 (April 2020 to March 2024) were analyzed across 335 administrative units in Japan. Units were categorized as urban, local, or depopulated based on population size and density, and paired t-tests were performed.
RESULTS: Nationwide PP decreased from 3.68% to 3.38%, representing an 8.15% reduction, during the study period. Across 335 administrative units, the regional mean PP decreased from 4.16% to 3.86% (mean difference: 0.30%, p<0.001). Statistically significant reductions were observed across all regional categories, including urban (3.37% to 3.08%), local (3.92% to 3.63%), and depopulated areas (4.74% to 4.42%) (all p<0.001). PP remained consistently higher in depopulated areas than in urban areas throughout the study period.
CONCLUSIONS: A nationwide reduction in polypharmacy was observed in Japan following the 2022 outcome-based medical fee revision during the COVID-19 pandemic. Although reductions were observed across all regional categories, polypharmacy remained consistently higher in depopulated areas, suggesting persistent regional disparities and the need for tailored strategies in these areas.
METHODS: A serial cross-sectional study was conducted using NDB Open Data, an aggregated national reimbursement claims database published by the Ministry of Health, Labour and Welfare. Polypharmacy was defined as the use of ≥7 concurrent medications for >2 weeks, based on criteria adopted for Japanese outcome-based reimbursement incentives. The outcome, polypharmacy proportion (PP), was defined as the proportion of polypharmacy prescriptions among all annual prescriptions. Data from FY2020 to FY2023 (April 2020 to March 2024) were analyzed across 335 administrative units in Japan. Units were categorized as urban, local, or depopulated based on population size and density, and paired t-tests were performed.
RESULTS: Nationwide PP decreased from 3.68% to 3.38%, representing an 8.15% reduction, during the study period. Across 335 administrative units, the regional mean PP decreased from 4.16% to 3.86% (mean difference: 0.30%, p<0.001). Statistically significant reductions were observed across all regional categories, including urban (3.37% to 3.08%), local (3.92% to 3.63%), and depopulated areas (4.74% to 4.42%) (all p<0.001). PP remained consistently higher in depopulated areas than in urban areas throughout the study period.
CONCLUSIONS: A nationwide reduction in polypharmacy was observed in Japan following the 2022 outcome-based medical fee revision during the COVID-19 pandemic. Although reductions were observed across all regional categories, polypharmacy remained consistently higher in depopulated areas, suggesting persistent regional disparities and the need for tailored strategies in these areas.
Conference/Value in Health Info
2026-09, ISPOR Asia Pacific 2026, Bangkok, Thailand
Value in Health, Volume 55, Issue S1
Code
HPR37
Topic
Health Policy & Regulatory
Topic Subcategory
Insurance Systems & National Health Care
Disease
No Additional Disease & Conditions/Specialized Treatment Areas