Impact of chronic obstructive pulmonary disease on severity and outcomes in COVID-19 patients: A systematic review

We conducted this systematic review to evaluate whether comorbid chronic obstructive pulmonary disease (COPD) increases the risk of severe disease and adverse outcomes among patients with coronavirus disease (COVID-19). We queried the PubMed and Embase databases for studies indexed till December 2020. We included studies that provided data on severe disease, hospitalization, intensive care unit (ICU) care, need for mechanical ventilation, or mortality among COVID-19 patients with and without COPD. We calculated the relative risk (RR) for each reported outcome of interest from each study and used a random-effects model to summarize our data. We retrieved 997 citations and included 110 studies published in 2020, in our review. Most publications reported the data retrieved from electronic records of retrospective patient cohorts. Only 27 studies were judged to be of high quality. COPD patients with COVID-19 had a significantly higher risk of severe disease (summary RR 2.44, 95% confidence interval [CI] 1.93-3.09), hospitalization (summary RR 1.91, 95% CI 1.70-2.14), ICU admission (summary RR 1.81, 95% CI 1.35-2.43), mechanical ventilation (summary RR 1.75, 95% CI 1.35-2.28), and mortality (summary RR 2.40, 95% CI 1.93-2.51), as compared to COVID-19 patients without COPD. All analyses showed significant between-study heterogeneity. We conclude that comorbid COPD significantly increases the risk of severe disease and adverse outcomes among COVID-19 patients.