Association Between Pneumonia and Chronic Otitis Media: A Nested Case-Control Study Using a National Health Screening Cohort

Background: Pneumonia and chronic otitis media (COM) share a common pathophysiological mechanism in terms of respiratory infection and inflammation, but the epidemiologic association between the 2 diseases has not been investigated. We investigated the association between an event of COM and previous events of pneumonia in a national cohort. Methods: Data from the Korean National Health Insurance Service-Health Screening Cohort were collected from 2002 to 2015. A 1:4 stratified cohort matched for age, sex, income, and residence region composing the COM group (n=23,436) and a control group (n=93,744) was selected. The crude and adjusted odds ratios (ORs) of pneumonia occurring before the index date for COM were analyzed using a conditional logistic regression model. In addition, ORs of the number of diagnoses of pneumonia (≥5 times vs. <5 times) for COM were analyzed. Results: The incidence of pneumonia (9.3%) was significantly higher (p<0.001) in the COM group than in the control group (7.2%). The ORs of pneumonia were significantly higher in the COM group than in the control group. Pneumonia (adjusted OR=1.31, 95% confidence interval [CI]=1.25–1.38, p<0.001) increased the ORs for COM in all ages and gender. Pneumonia being diagnosed ≥5 times before the index date showed higher ORs (adjusted OR=1.34, 95% CI=1.20–1.49, p<0.001) for COM than pneumonia being diagnosed <5 times. Conclusions: Our population-based nationwide cohort study indicates that diagnosis of pneumonia was significantly associated with an increased incidence of COM.