The association between current smoking and coronavirus disease 2019 (COVID-19) progression remains uncertain. We aim to provide up-to-date evidence of the role of cigarette smoking in COVID-19 hospitalisation, severity and mortality. On 23 February 2022 we conducted an umbrella review and a traditional systematic reviewviaPubMed/Medline and Web of Science. We used random-effects meta-analyses to derive pooled odds ratios of COVID-19 outcomes for smokers in cohorts of severe acute respiratory syndrome coronavirus 2 infected individuals or COVID-19 patients. We followed the Meta-analysis of Observational Studies in Epidemiology reporting guidelines. PROSPERO: CRD42020207003. 320 publications were included. The pooled odds ratio for currentversusnever or nonsmokers was 1.08 (95% CI 0.98–1.19; 37 studies) for hospitalisation, 1.34 (95% CI 1.22–1.48; 124 studies) for severity and 1.32 (95% CI 1.20–1.45; 119 studies) for mortality. Estimates for formerversusnever-smokers were 1.16 (95% CI 1.03–1.31; 22 studies), 1.41 (95% CI: 1.25–1.59; 44 studies) and 1.46 (95% CI 1.31–1.62; 44 studies), respectively. Estimates for ever-versusnever-smokers were 1.16 (95% CI 1.05–1.27; 33 studies), 1.44 (95% CI 1.31–1.58; 110 studies) and 1.39 (95% CI 1.29–1.50; 109 studies), respectively. We found a 30–50% excess risk of COVID-19 progression for current and former smokers compared with never-smokers. Preventing serious COVID-19 outcomes, including death, seems the newest compelling argument against smoking.

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record.

Purpose Since the first Italian case of SARS-CoV-2 was detected in Lombardy (Northern Italy)  Italy quickly became one of the worst-affected European countries, with a severe impact on health-care workers (HCWs). In the first epidemic, HCWs accounted for 12% of all national COVID-19 cases. We evaluated the burden of COVID-19 among HCWs and other non-health-care workers (nHCWs) in a large Italian hospital. Methods From March 1st to May 31st 2020, we performed a retrospective study at ASST Civil Hospital, in the Province of Brescia, Lombardy. The study population included all hospital personnel (n = 9265), categorized by professional status. Results A SARS-CoV-2 test was performed in 3572 workers (38.5%), with a positive result in 552 (5.9% of all hospital personnel). The temporal trend of SARS-CoV-2 cases in hospital staff broadly reflected that in the community, with a great majority of infections occurred during March 2020 (87.7%). From April onward, a steep decrease of positive cases was observed among hospital personnel, while in the community the decrease was much slower. Medical doctors (8.9%) and nurses (8.5%) were the most affected professional categories with a significantly higher risk of SARS-CoV-2 infection (OR 1.436 and OR 1.410, respectively p < 0.0001). HCWs in COVID-19 units presented a significantly higher risk of infection compared to HCWs in non-COVID units (p < 0.001). Conclusion HCWs were severely affected by the COVID-19 epidemic, probably associated with an overwhelming burden of work and lack of preparedness in prevention of nosocomial transmission of the infection. The rapid decrease of COVID-19 spread in the hospital, registered before the one in the community, suggests that the adopted preventive measures were effective.

No abstract