The Association Between COVID-19 Vaccination and the Healthcare Resource Use Related to COVID-19 in Typical Rural Residents in Japan
Author(s)
Ayako Shoji, PhD1, Yuriko Hagiwara, BSc, MSc, PhD2, Kenichi Kudo, B.S.3, Koichi Murashita, M.A.4, Shigeyuki Nakaji, Ph.D.4, Ataru Igarashi, Ph.D.5.
1University of Tokyo, Bunkyo-ku, Japan, 2The University of Tokyo, Tokyo, Japan, 3ICI Inc., Tokyo, Japan, 4Hirosaki University, Hirosaki, Japan, 5Facul. of Pharm. Dept. of Health Economics & Outcomes Research, The University of Tokyo, Tokyo, Japan.
1University of Tokyo, Bunkyo-ku, Japan, 2The University of Tokyo, Tokyo, Japan, 3ICI Inc., Tokyo, Japan, 4Hirosaki University, Hirosaki, Japan, 5Facul. of Pharm. Dept. of Health Economics & Outcomes Research, The University of Tokyo, Tokyo, Japan.
OBJECTIVES: The COVID-19 vaccination rate is decreasing, although it is recommended in high-risk populations. This study aims to confirm the association between the vaccination and healthcare resource use during a transition period from Delta to Omicron phase in Japan.
METHODS: We used a claims data and vaccination records in a typical aging society in Hirosaki city, which were individually and electronically linked. We matched residents vaccinated to those unvaccinated in the period from 1 March 2021 to 30 June 2022 using a risk-set sampling by considering age, sex, and Charlson Comorbidity Index (CCI) as well as residence in care homes where preventive measures were thoroughly implemented. After the exact matching, PS matching with a 1% caliper was performed. We compared the incidence of COVID-19-related hospitalization and serious conditions with intensive care unit or artificial respiration, and health resource use associated with them between vaccinated and unvaccinated groups considering same factors as matching.
RESULTS: After matching, 48,735 vaccinated individuals matched to 83,044 unvaccinated individuals. Mean age was around 67 years, mean CCI was around 1.65, and mean care level was around 0.5 in both groups. The incidence rate of hospitalization and serious conditions after COVID-19 onsets were significantly higher in the unvaccinated group than in the vaccinated group (HR 2.25, 95% CI 1.93-2.56; HR 1.40, 95% CI 1.29-1.52). Male, higher age, higher CCI, and higher care level were associated with high incidence. The inpatient cost was also significantly higher in the unvaccinated group (RR 1.64 95% CI 1.33-2.02), but the length of months under serious conditions was not different between groups (RR 1.20, 95% CI 0.98-1.47).
CONCLUSIONS: We observed a low incidence of hospitalization and serious conditions and low inpatient costs in the vaccinated population while no significant difference in the duration of serious conditions.
METHODS: We used a claims data and vaccination records in a typical aging society in Hirosaki city, which were individually and electronically linked. We matched residents vaccinated to those unvaccinated in the period from 1 March 2021 to 30 June 2022 using a risk-set sampling by considering age, sex, and Charlson Comorbidity Index (CCI) as well as residence in care homes where preventive measures were thoroughly implemented. After the exact matching, PS matching with a 1% caliper was performed. We compared the incidence of COVID-19-related hospitalization and serious conditions with intensive care unit or artificial respiration, and health resource use associated with them between vaccinated and unvaccinated groups considering same factors as matching.
RESULTS: After matching, 48,735 vaccinated individuals matched to 83,044 unvaccinated individuals. Mean age was around 67 years, mean CCI was around 1.65, and mean care level was around 0.5 in both groups. The incidence rate of hospitalization and serious conditions after COVID-19 onsets were significantly higher in the unvaccinated group than in the vaccinated group (HR 2.25, 95% CI 1.93-2.56; HR 1.40, 95% CI 1.29-1.52). Male, higher age, higher CCI, and higher care level were associated with high incidence. The inpatient cost was also significantly higher in the unvaccinated group (RR 1.64 95% CI 1.33-2.02), but the length of months under serious conditions was not different between groups (RR 1.20, 95% CI 0.98-1.47).
CONCLUSIONS: We observed a low incidence of hospitalization and serious conditions and low inpatient costs in the vaccinated population while no significant difference in the duration of serious conditions.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
CO233
Topic
Clinical Outcomes, Economic Evaluation, Real World Data & Information Systems
Topic Subcategory
Comparative Effectiveness or Efficacy
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, Vaccines