1Università di Modena e Reggio Emilia, Modena, Italy
2Centre for Statistics in Medicine, University of Oxford, Oxford
3Ottawa Methods Centre, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
4Annals of Internal Medicine, Philadelphia, Pennsylvania, USA
5Nordic Cochrane Centre, Copenhagen, Denmark
6Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
7School of Nursing and Midwifery, Trinity College, Dublin, Republic of Ireland
8UK Cochrane Centre, Oxford
9Departments of Medicine, Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
10Kleijnen Systematic Reviews, York
11School for Public Health and Primary Care (CAPHRI), University of Maastricht, Maastricht, Netherlands
12Department of Epidemiology and Community Medicine, Faculty of Medicine, Ottawa, Ontario, Canada