PPT Slide
Appraisal process: Grades of Recommendation
A1 Level I RCTs, no heterogeneity
A2 Level II RCTs, no heterogeneity
B1 Level I RCTs, heterogeneity
B2 Level II RCTs, heterogeneity
C1 Observational studies, CIs all on one side of threshold NNT
C2 Observational studies, CIs overlap threshold NNT
Adapted from: Gordon H. Guyatt, John C. Sinclair, Robert Hayward, Deborah J. Cook, Richard J. Cook, for the Evidence-Based Medicine Working Group. Method for Grading Health Care Recommendations JAMA 1995;274(22):1800-4