GRADE guidelines 3: rating the quality of evidence - introduction

Balshem H, Helfand M, Schunemann H, Oxman AD, Kunz R, Brozek J, Vist GE, Falck-Ytter Y, Meerpohl J, Norris S, Guyatt GH. GRADE guidelines 3: rating the quality of evidence - introduction. Journal of Clinical Epidemiology 2011; 64: 401-6. . Vitenskapelig artikkel 2011.Journal of Clinical Epidemiology 2011; 64: 401-6.