Body mass index and outcome in patients with COVID-19: A dose–response meta-analysis

•Obesity was associated with mortality and severity in patients with COVID-19.•Dose–response meta-analysis demonstrate an increase of 5% risk for poor outcome for every 5kg/mg2 increase in body mass index.•The relationship departed from linearity and became steeper from 30–35kg/mg2 onwards. There is mounting evidence related to the association between obesity and severity of COVID-19. However, the direct relationship of the increase in the severe COVID-19 risk factors, with an increase in body mass index (BMI), has not yet been evaluated. This meta-analysis aims to evaluate the dose–response relationship between body mass index (BMI) and poor outcome in patients with COVID-19. A systematic literature search was conducted using PubMed, Europe PMC, ProQuest, and the Cochrane Central Database. The primary outcome was composite poor outcome composed of mortality and severity. The secondary outcomes were mortality and severity. A total of 34,390 patients from 12 studies were included in this meta-analysis. The meta-analysis demonstrated that obesity was associated with composite poor outcome (OR 1.73 [1.40, 2.14], P