Regional variation in COVID-19-related outcomes and health services in Japan

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K21103
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0908:Society medicine, nursing, and related fields
• Research Institution: National Center for Global Health and Medicine
• Principal Investigator: Mimura Wataru 国立研究開発法人国立国際医療研究センター, 臨床研究センター, 上級研究員 (80895483)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: COVID-19 / 地域差 / ヘルスサービスリサーチ

Outline of Final Research Achievements

We evaluated the relationship between vaccination and the COVID-19 healthcare delivery system during the Omicron-predominant period, as well as regional differences in the healthcare delivery system. The odds ratio for hospitalization due to vaccination compared to non-vaccination tended to decrease with increasing number of doses. The median odds ratio (MOR: the median odds ratio when comparing COVID-19 patients with the same background in municipalities with high and low hospitalization tendencies) was 1.70 during the BA.1/BA2 outbreak period, while it was 1.18 during the BA.5 outbreak period. Regional differences in hospitalization were observed among municipalities during the BA.1/BA2 outbreak period, but these differences narrowed during the BA.5 outbreak period, suggesting the impact of the fourth vaccination.

Free Research Field

疫学

Academic Significance and Societal Importance of the Research Achievements

COVID-19による感染者数や死亡者数は各地域によって差があることが報告されている．地域格差の定量化と格差の要因の評価は，COVID-19のような有事の対応の問題点を示し，介入対象を明確化するために重要である．本研究は，市町村レベルでのCOVID-19入院及び治療薬処方に関する地域差及びワクチン接種との関連を示した．本研究における成果は公平な医療資源の配分や効果的な感染症対策の策定に貢献する可能性がある．また，個々の要因を考慮した分析により，より精密な予防策や対策の提案が可能となり，社会全体の健康状態の改善に寄与することが期待される．