SARS-CoV-2 infection increases long-term risk of pneumonia in an urban population: an observational cohort study up to 46 months post-infection

Abstract Background COVID-19 could increase susceptibility to future pulmonary infections. Given the sheer number of individuals infected by SARS-CoV-2, increased prevalence of future pulmonary infections could be a public health concern. Methods We conducted a retrospective study to determine whether COVID-19 is associated with increased incidence of future pneumonia. In an urban population in Montefiore Health System in the Bronx between 03/1/2020 and 01/31/2024, there were 64,376 patients with a prior history of COVID-19, 1.2 million patients without (controls), and 8468 patients with influenza without COVID-19. Controls were propensity-matched. Multivariate Cox adjusted hazard ratios (aHR) with 95% confidence interval (CI) accounting for confounders were calculated. Outcomes were also analyzed with respect to comorbidities, median incomes, insurance status, and unmet social needs. Results Hospitalized COVID-19 (aHR=3.69, 95%CI[3.29,4.15]) and non-hospitalized COVID-19 (aHR=1.40[1.27,1.55]) patients had higher risk of developing future pneumonia compared to controls. Hospitalized COVID-19 patients experienced more recurrent pneumonia episodes (2.3 cases/patient, p<0.05) compared to non-hospitalized COVID-19 patients (1.93 cases/patient, p<0.05), who also had a higher rate of recurrence than the control group (1.71 cases/patient). Individuals on Medicaid (aHR=1.40 [1.26,1.55]), Medicare (aHR=2.39 [2.12,2.69]) (relative to private insurance) or with unmet social needs (aHR=1.34 [1.12,1.60]) were at even higher risks of outcomes. Hospitalized COVID-19 patients had a higher adjusted risk of outcomes compared to the influenza patients (aHR=2.89, 95% CI [2.26, 3.69]). Risk of outcomes varied by COVID-19 variants/waves. Conclusions COVID-19 is associated with a higher risk of new-onset pneumonia. Patients with lower socioeconomic status or unmet needs were at higher risk.