THE ASSOCIATION BETWEEN PNEUMOCOCCAL VACCINATION HISTORY AND THE INCIDENCE OF PNEUMONIA AND HEALTHCARE RESOURSE USE IN 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, 3Integrated Clinical Care Informatics, Inc., Tokyo, Japan, 4Hirosaki University, Hirosaki, Japan, 5Tokyo Univ. Facul. of Pharm. Dept. of Health Economics & Outcomes Research, Tokyo, Japan
1University of Tokyo, Bunkyo-ku, Japan, 2The University of Tokyo, Tokyo, Japan, 3Integrated Clinical Care Informatics, Inc., Tokyo, Japan, 4Hirosaki University, Hirosaki, Japan, 5Tokyo Univ. Facul. of Pharm. Dept. of Health Economics & Outcomes Research, Tokyo, Japan
OBJECTIVES: Pneumococcal vaccination is currently recommended in population aged ≥65 years and in those aged between 60-64 years and with impaired heart, kidney, or respiratory organ functions to prevent complications. However, the coverage rate is only 40-50%. This study aimed to assess the associations between vaccination use and incidence of pneumonia in a typical aging population with fewer children in Hirosaki city.
METHODS: We used claims data and vaccination records. These were individually linked under the next-generation medical infrastructure low, which is the only framework to link these records in Japan. We matched vaccinated residents to unvaccinated residents from January 1, 2018, to December 31, 2022, using exact matching and propensity score matching with 1% caliper taking into consideration age, sex, Charlson Comorbidity Index (CCI), and residence in care homes (where thorough protection against infectious diseases is conducted). We compared incidence of pneumonia and the treatment period between the vaccinated and unvaccinated groups using multivariate analyses, considering the same factors as matching.
RESULTS: After matching, 10,295 vaccinated and 19,799 unvaccinated individuals were identified. The mean age was approximately 72.5 years, the mean CCI was approximately 1.80, and the proportion living in care homes was approximately 0.5% in both groups. Incidence rate of pneumonia was significantly higher in the unvaccinated group than in the vaccinated group (HR 1.10, 95% CI 1.00-1.21). Treatment duration was associated with female sex, higher age, and higher CCI (RR 0.64, 95% CI 0.60-0.68; RR 1.07, 95% CI 1.07-1.08; RR 1.13, 95% CI 1.11-1.14, respectively) along with the incidence but not with no vaccination (RR 1.06, 95% CI 0.99-1.13).
CONCLUSIONS: We observed a low incidence of pneumonia in the vaccinated population in an area with low indirect effects from pediatric to elderly population, whereas background risk factors had a greater impact on the duration of treatment than vaccination.
METHODS: We used claims data and vaccination records. These were individually linked under the next-generation medical infrastructure low, which is the only framework to link these records in Japan. We matched vaccinated residents to unvaccinated residents from January 1, 2018, to December 31, 2022, using exact matching and propensity score matching with 1% caliper taking into consideration age, sex, Charlson Comorbidity Index (CCI), and residence in care homes (where thorough protection against infectious diseases is conducted). We compared incidence of pneumonia and the treatment period between the vaccinated and unvaccinated groups using multivariate analyses, considering the same factors as matching.
RESULTS: After matching, 10,295 vaccinated and 19,799 unvaccinated individuals were identified. The mean age was approximately 72.5 years, the mean CCI was approximately 1.80, and the proportion living in care homes was approximately 0.5% in both groups. Incidence rate of pneumonia was significantly higher in the unvaccinated group than in the vaccinated group (HR 1.10, 95% CI 1.00-1.21). Treatment duration was associated with female sex, higher age, and higher CCI (RR 0.64, 95% CI 0.60-0.68; RR 1.07, 95% CI 1.07-1.08; RR 1.13, 95% CI 1.11-1.14, respectively) along with the incidence but not with no vaccination (RR 1.06, 95% CI 0.99-1.13).
CONCLUSIONS: We observed a low incidence of pneumonia in the vaccinated population in an area with low indirect effects from pediatric to elderly population, whereas background risk factors had a greater impact on the duration of treatment than vaccination.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
CO136
Topic
Clinical Outcomes
Topic Subcategory
Comparative Effectiveness or Efficacy
Disease
SDC: Infectious Disease (non-vaccine)