[1] Dutch Coll Gen Practitioners, Dept Guideline Dev & Res, Utrecht, Netherlands
[2] McMaster Univ, Hamilton, ON, Canada
[3] McMaster Univ, Dept Hlth Res Methods Evidence & Impact, Hamilton, ON L8S 4L8, Canada
[4] Univ Toronto, Dept Med, Toronto, ON, Canada
[5] Norwegian Inst Publ Hlth, Oslo, Norway
[6] Innlandet Hosp Trust, Div Gjovik, Dept Med, Gjovik, Norway
[7] Univ Washington, Seattle, WA 98195 USA
[8] Queens Univ, Dept Med, Div Neurol, Kingston, ON, Canada
[9] Univ Calif Davis, Sacramento, CA 95817 USA
[10] All India Inst Med Sci, New Delhi, India
[11] Univ Med Ctr Groningen, Groningen, Netherlands
[12] Western Univ, Dept Anesthesia & Perioperat Med, London, ON, Canada
[13] Western Univ, Dept Epidemiol & Biostat, London, ON, Canada
[14] Univ Hosp Geneva, Div Gen Internal Med, CH-1211 Geneva, Switzerland
[15] NUI Galway, Galway, Ireland
[16] Oslo Univ Hosp, Oslo, Norway
[17] Univ Hosp Geneva, Div Clin Epidemiol, CH-1211 Geneva, Switzerland