SARS-CoV-2 Infection and the Long-Term Risk of Pneumonia in an Urban Population: An Observational Cohort Study up to 46 Months After Infection

BACKGROUND: Coronavirus disease 2019 (COVID-19) could increase susceptibility to future pulmonary infections. Given the sheer number of individuals infected by severe acute respiratory syndrome coronavirus 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 1 March 2020 and 31 January 2024, there were 64 376 patients with a 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 (aHRs) with 95% confidence interval (CIs) accounting for confounders were calculated. Outcomes were also analyzed with respect to comorbid conditions, median incomes, insurance status, and unmet social needs. RESULTS: Hospitalized (aHR, 3.69 [95% CI, 3.29-4.15]) and nonhospitalized (aHR, 1.40 [1.27-1.55]) patients with COVID-19 had higher risks of future pneumonia than controls. Hospitalized patients with COVID-19 experienced more recurrent pneumonia episodes than nonhospitalized patients with COVID-19 (2.3 vs 1.93 cases per patient, respectively; P < .05), who also had a higher rate of recurrence than the control group (1.71 cases per patient). Individuals on Medicaid (aHR, 1.40 [95% CI, 1.26--1.55]) or Medicare (2.39 [2.12--2.69]) (relative to private insurance) and those with unmet social needs (aHR, 1.34 [1.12-1.60]) were at even higher risks of outcomes. Hospitalized patients with COVID-19 had a higher adjusted risk of outcomes than patients with influenza (aHR, 2.89 [95% CI, 2.26-3.69]). Risks 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.