Annette AM Gerritsen 1
, Rob JPM Scholten 2
, Willem JJ Assendelft 3
, Herman Kuiper 4
, Henrica CW de Vet 5
and Lex M Bouter 6 
1Institute for Research in Extramural Medicine, VU University Medical Center, Amsterdam, The Netherlands
2Dutch Cochrane Center/Department of Clinical Epidemiology and Biostatistics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
3Dutch College of General Practitioners, Utrecht
4Department of Neurology, Flevoziekenhuis, Almere, The Netherlands
5Institute for Research in Extramural Medicine, VU University Medical Center, Amsterdam, The Netherlands
6Institute for Research in Extramural Medicine, VU University Medical Center, Amsterdam, The Netherlands