Effect of chronic obstructive pulmonary disease and smoking on the outcome of COVID-19.

OBJECTIVE: To investigate the association between chronic obstructive pulmonary disease (COPD) and smoking with outcome in patients with COVID-19.METHODS: A systematic literature search was performed using PubMed, EuropePMC, SCOPUS and the Cochrane Central Database. A composite of poor outcome, mortality, severe COVID-19, the need for treatment in an intensive care unit (ICU) and disease progression were the outcomes of interest.RESULTS: Data on 4603 patients were pooled from 21 studies. COPD was associated with an increased risk for composite poor outcome (OR 5.01, 95%CI 3.06-8.22; P < 0.001; I² 0%), mortality (OR 4.36, 95%CI 1.45-13.10; P = 0.009; I² 0%), severe COVID-19 (OR 4.62, 95%CI 2.49-8.56; P < 0.001; I² 0%), ICU care (OR 8.33, 95%CI 1.27-54.56; P = 0.03; I² 0%), and disease progression (OR 8.42, 95%CI 1.60-44.27; P = 0.01; I² 0%). Smoking was found to increase the risk of composite poor outcome (OR 1.52, 95%CI 1.16-2.00; P = 0.005; I² 12%), and subgroup analysis showed that smoking was significant for increased risk of severe COVID-19 (OR 1.65, 95%CI 1.17-2.34; P = 0.004; I² 11%). Current smokers were at higher risk of composite poor outcomes (OR 1.58, 95%CI 1.10-2.27; P = 0.01; I² 0%) than former/non-smokers.CONCLUSION: Our systematic review and meta-analysis revealed that COPD and smoking were associated with poor outcomes in patients with COVID-19.