Abstract
OBJECTIVES: To evaluate the risk of invasive pneumococcal disease (IPD) and non-bacteraemic pneumonia (NBP)/acute otitis media (AOM)/sinusitis in Japanese individuals under 19 years of age with chronic medical conditions (CMCs) compared with those without. DESIGN: An observational, retrospective, cohort study. SETTING: A large, longitudinal health insurance claims database in Japan (JMDC database). PARTICIPANTS: A total of 12.3 million individuals aged <19 years identified between 2006 and 2022 were included in the analysis. Seventeen CMCs as well as IPD and NBP/AOM/sinusitis were identified using diagnostic codes from the International Statistical Classification of Diseases and Related Health Problems V.10. PRIMARY OUTCOME MEASURE: Adjusted incidence rate ratios (IRRs) for IPD and NBP/AOM/sinusitis for individuals with CMCs versus those without CMCs were calculated using multivariate Poisson regression models with age and sex as covariates. RESULTS: The incidence rate of IPD was higher in individuals with a CMC (0.9 (95% CI: 0.8 to 0.9)) than in those without (0.1 (95% CI: 0.1 to 0.1)). A similar trend was observed for the incidence rate of NBP/AOM/sinusitis, with rates of 928.7 (95% CI: 927.4 to 929.9) in individuals with a CMC compared with 433.2 (95% CI: 432.8 to 433.7) in those without. The risk of IPD increases with the number of CMCs. The IRRs for IPD for those with one CMC and with two or more CMCs were 7.2 (95% CI: 6.4 to 8.1) and 128.1 (95% CI: 114.8 to 143.0), respectively, compared with individuals without a CMC. The IRRs for IPD in the immunocompromised and immunocompetent groups were 156.1 (95% CI: 133.4 to 182.7) and 16.3 (95% CI: 14.6 to 18.1), respectively. The IRRs for NBP/AOM/sinusitis were 1.9 (95% CI: 1.9 to 1.9) and 2.1 (95% CI: 2.1 to 2.2) for individuals with one CMC and with two or more CMCs, respectively. CONCLUSION: Individuals aged <19 years with CMC are at higher risk of developing IPD and NBP/AOM/sinusitis, compared with those without. Our findings suggest the importance of vaccination against pneumococcal diseases in paediatric populations with CMCs.