Julian P. T. Higgins is Professor of Evidence Synthesis at Bristol Medical School, University of Bristol, UK. He has worked in methods for systematic review and meta-analysis for over 25 years and acts as Senior Methods Advisor to Cochrane.
James Thomas is Professor of Social Research and Policy at the EPPI-Centre, UCL Institute of Education. He has broad interests in systematic review methodology and tools and is Director of the Systematic Reviews Facility for the Department of Health, England.