Secondhand Smoke and Streptococcal Infection in Young Children Under Japan's Voluntary Tobacco-Free Policy

Abstract Tobacco-free policy in Japan lags behind those of most developed countries. Evidence is required to promote strong implementation of existing policies. This study aimed to assess whether exposure to secondhand smoke (SHS) influences the incidence of streptococcal infection in young children, to further support the need for effective tobacco-free policies in Japan. This study used medical administrative claim and health check data from the Japan Health Insurance Association Fukuoka branch. Participants were beneficiaries' dependents younger than age 4 years. Exposure was defined as SHS from beneficiaries' smoking, each year during 2011–2014. The outcome was incidence of streptococcal infection, diagnosed with and without laboratory testing. Logistic regression analysis was performed to yield odds ratios (ORs) of associations with the outcome and 95% confidence intervals (CIs). This study included a total of 5743 children. The proportion of all participants with a record of streptococcal infection ...