1. Kleijnen Systematic Reviews Ltd., 6 Escrick Business Park, Escrick, York YO19 6FD, UK
2. KJ Research, Rosemere, QC, Canada J7A 4N8
3. BeSyRe Bekkering Systematic Reviews, 2440 Geel, Belgium
4. Center for Evidence Based Medicine, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
5. Leuven Centre for Cancer Prevention, University Hospital Leuven, 3000 Leuven, Belgium
6. 2nd Department of Internal Medicine, Jagiellonian University Medical College, 31-066 Krakow, 8 Skawinska Street, Poland
7. School for Public Health and Primary Care (CAPHRI), University of Maastricht, 6200 MD Maastricht, The Netherlands