Association between chronic rhinosinusitis and pneumonia: a longitudinal follow-up study using a national health screening cohort.

This study was aimed to compare the risk of pneumonia between patients with chronic rhinosinusitis (CRS) and those without CRS (control) in a Korean population. The population aged 40 years or over was included from the Korean National Health Insurance Service-Health Screening Cohort. Participants with CRS (n = 6393) and controls (n = 25,572) were selected by 1:4 matching for age, sex, income, region of residence, and history of pneumonia for the previous 1 year. The index date (ID) of the controls was set as the treatment date of their matched CRS participants. The incidence of pneumonia after the ID was measured from 2003 to 2015. Simple and multiple linear regressions were performed to calculate estimated values (EVs) and 95% confidence intervals (CIs) for 1-y post-ID pneumonia, 2-y post-ID pneumonia, and 3-y post-ID pneumonia in CRS participants compared to controls. Statistical significance was noted in the 3-y post-ID period (EV = 0.017, 95% CI = 0.002-0.031, P = 0.030). In the subgroup analyses according to age and sex, statistical significance was seen in the younger age group (< 60 years old) in the 3-y post-ID period and in the female group in the 1-y and 3-y post-ID periods. This study revealed an increased risk for pneumonia following a diagnosis of CRS.