Indeed, this difference is at the heart of the shift to evidence-based medical guidelines. The traditional expert-generated guidelines just gave undifferentiated pronouncements of what physicians should and should not do. Evidence-based guidelines, for the first time, explicitly tell physicians the quality of the evidence underlying each suggested practice. Signaling the quality of the evidence lets physicians (and patients) know when a guideline is written in stone and when it’s just their best guess given limited information.
