Atkins, David; Eccles, Martin; Flottorp, Signe; Guyatt, Gordon H; Henry, David; Hill, Suzanne; Liberati, Alessandro; O'Connell, Dianne; Oxman, Andrew David; Phillips, Bob; Schünemann, Holger; Edejer, Tessa Tan-Torres; Vist, Gunn Elisabeth; Williams, John W (Journal article; Peer reviewed, 2004-12-22)
BACKGROUND: A number of approaches have been used to grade levels of evidence and the strength of recommendations. The use of many different approaches detracts from one of the main reasons for having explicit approaches: ...