I am Professor of Clinical Epidemiology at the University of Bristol, where I am Co-Director of Bristol Technology Assessment Group, one of several External Assessment Groups that supports NICE guidance committees and other policy makers. I am also Co-Director of the Bristol Evidence Synthesis for Screening (BESS) Group, one of three groups that conducts evidence syntheses to supports the UK National Screening Committee. I have over 25 years’ experience of systematic reviews combining an interest in methodological research with substantive reviews in academic and commercial environments. My methodological research has covered the full spectrum of systematic reviews including literature searching, quality assessment, synthesising results and communicating findings. I have a particular interest in risk of bias tools. I lead the development of QUADAS and its successors QUADAS-2 and QUADAS-3 for diagnostic accuracy studies, the ROBIS tool for systematic reviews and ROB-NMA for network meta-analyses. I was a steering group member for the development of the PROBAST tool for prediction modelling studies, QUADAS-C for comparative accuracy studies, and QUAPAS for predictive accuracy studies. I also contributed to the development of RoB 2 for randomised trials and ROBINS-I for non-randomised studies of interventions. I have also contributed to reporting guidelines as a member of the working groups for PRISMA-2020.