Association of Bariatric Surgery with Clinical Outcomes of SARS-CoV-2 Infection: a Systematic Review and Meta-analysis in the Initial Phase of COVID-19 Pandemic

INTRODUCTION: Obesity worsens clinical outcomes of coronavirus disease 2019 (COVID-19). The aim of this study was to measure the association between history of bariatric surgery and the severity of COVID-19. METHODS: Data source included PubMed/MEDLINE, Scopus, Google Scholar, and pre-print servers between January and November 1, 2020. Literature was screened and selected to extract the relevant data. The two outcomes of this meta-analysis were the difference in mortality and hospitalization rates in patients with SARS-CoV-2 infection with and without history of bariatric surgery. Random-effect models were used to estimate the pooled effects. RESULTS: The systematic review yielded 3 retrospective studies on 9022 patients. The risk of mortality without previous bariatric surgery was 133 per 1000 cases and its risk with previous bariatric surgery was 33 per 1000 (summary OR 0.22, 95% CI 0.19–0.26). No heterogeneity was observed between the included studies (I(2) = 0%, P = 0.98 for heterogeneity). In the pooled analysis, the hospitalization rate in patients without previous bariatric surgery was 412 per 1000 cases and its rate in patients with previous bariatric surgery was 164 per 1000 (summary OR 0.28, 95% CI 0.12–0.65). No heterogeneity was observed between the included studies (I(2) = 0%, P = 0.71 for heterogeneity). There was a substantial risk of bias across the studies for confounding and selection bias. CONCLUSION: Findings of this meta-analysis of observational studies suggest that prior bariatric surgery is associated with a lower rate of mortality and hospital admission in patients with obesity who become infected with SARS-CoV-2. Confirmation of these findings will require larger studies with better quality data.