Jos Kleijnen is a physician (University of Maastricht, Netherlands), and is specialised as a clinical epidemiologist. Currently, he is director of an independent company, Kleijnen Systematic Reviews Ltd – www.systematic-reviews.com, which prepares systematic reviews and health technology assessments for various commissioners, and provides training courses in these areas. Previously, he was professor and director of the Centre for Reviews and Dissemination at the University of York; and director of the Dutch Cochrane Centre at the University of Amsterdam. His interests include: methodology of patient related research, health technology assessment, placebo effects, diagnostic and screening procedures, dissemination and implementation of research-based evidence, Evidence-based medicine, systematic reviews and the Cochrane Collaboration.