Risk of bias table for MRPs following studies included in trial registries.

*The research status of Shamliyan 2012a refers to completed and terminated trials.**The MRP of Tfelt-Hansen 2011 is based on the GKS registry only.+ means low risk of bias; - means high risk of bias;? means unclear risk of bias.Follow-up time:>24 months: +. -. follow-up time not given/or could not be estimated:?.Methodology used to identify journal publication: electronic search and author contact and/or search in trial registry: +. only author contact (with a response rate of ≥80%): +. only author contact (with a response rate -. only search in trial registry or only 1 database: -. methodology not given:?.Adjustment for confounders: if an analysis for factors associated with the journal publication was carried out: +. if no analyses were carried out: -.Matching criteria: if ≥2 matching criteria given: +. if -. matching criteria not given in MRP:?.Research status: completed registry entries: +. completed and initiated mixed: -. not mentioned:?.Sampling method: all trials, random sample or consecutive trials: +. if only investigator responded to questionnaire for this sample: -. sampling method not given (e.g., without the word “all”):?.Risk of bias table for MRPs following studies included in trial registries.