Risk factors for community-acquired respiratory infections in a non-pandemic context: Secondary analysis of the PRIMIT study.

ObjectivesRespiratory tract infection (RTI) incidence varies between people, but little is known about why. The aim of this study is therefore to identify risk factors for acquiring RTIs.MethodsWe conducted a secondary analysis of 16,908 participants in the PRIMIT study, a pre-pandemic randomised trial showing handwashing reduced incidence of RTIs in the community. Data was analysed using multivariable logistic regression analyses of self-reported RTI acquisition.ResultsAfter controlling for handwashing, RTI in the previous year (1 to 2 RTIs: adjusted OR 1.96, 95% CI 1.79 to 2.13, pConclusionsPrevious RTIs, chronic lung conditions, skin conditions that prevent handwashing, and the presence of household children predispose to RTI acquisition. Further research is needed to understand how host and microbial factors explain the relationship between previous and future RTIs.