Risk of bias in individual studies
Two methodologists independently assessed the risk of bias in individual studies (CS, DdS) as did small groups of task force members (all authors). The Cochrane Risk of Bias tool 2 (ROB2)11Higgins JP, Altman DG, Gøtzsche PC, Jüni P, Moher D, Oxman AD, Savovic J, Schulz KF, Weeks L, Sterne JAC. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials. BMJ (Clinical research ed) 2011;343:d5928. was used for trials, ROBINS-I22Sterne JAC, Hernán MA, Reeves BC, Savović J, Berkman ND, Viswanathan M. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions BMJ 2016;355:i4919. for observational studies and QUADAS 233Whiting PF, Rutjes AW, Westwood ME, Mallett S, Deeks JJ, Reitsma JB, Leeflang MM, Sterne JA, Bossuyt PM. QUADAS-2: a revised tool for the quality assessment of diagnostic accuracy studies. Ann Intern Med 2011;155(8):529-536. for diagnostic studies. Arbitration was available from two senior clinicians (GR, MW) but there was 100% agreement in the risk of bias assessments.