Methods
We followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines (Supplementary Table S1) in the reporting of this study; the study methodology adhered to the Cochrane Handbook 27, 28. Evidence certainty assessment was based on the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria for prognostic factors 29. The protocol was prospectively registered with PROSPERO (CRD42020142004).