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).