Patients with coronavirus disease 2019 and spontaneous pneumothorax: a propensity-matched, multicentre case-control study

OBJECTIVES: Pneumothorax and pneumomediastinum have been frequently reported in coronavirus disease-19 (COVID-19), thus complicating the patient's overall health-care management and survival rate. The goal of this study was to evaluate the outcomes of patients with COVID-19 who developed spontaneous pneumothorax (SPN) or spontaneous pneumomediastinum (SPM). METHODS: In this Italian multicentre retrospective cohort study, medical records of non-vaccinated COVID-19 patients, from March 2020 to May 2021, were analysed. To reduce the risk of bias due to unbalanced groups, a propensity score matching approach was applied using logistic regression to estimate propensity scores. Separate multivariable generalized linear models were then used to assess the risk of in-hospital death and other outcomes. RESULTS: A total of 474 patients were assessed, 72 of whom developed SPN or SPM. In separate multivariable generalized linear model regression analyses of the unmatched cohort, SPN [odds ratio (OR) 2.44, 95% confidence interval (CI) 1.7-5.55; P = 0.031] was associated with an increase in the in-hospital death rate, results confirmed even after matching the 2 cohorts. SPM (OR 1.21, 95% CI 1.13-1.30, P < 0.001) and SPN (OR 1.34, 95% CI 1.26-1.43, P < 0.001) were associated with an increase in the length of hospital stay. The risk of in-hospital death also increased with age, comorbidities (classified by the Charlson comorbidity index) and smoking habits. CONCLUSIONS: SPN in hospitalized COVID-19 patients may be associated with an increased risk of in-hospital death and prolonged hospitalization.