Grading Recommendations
In the summary table below and the rest of this document we use the Strength of
Recommendation Taxonomy (SORT) proposed by Ebell and colleagues (1) to grade
recommendations based on the quality and consistency of relevant evidence:
Strength of
Recommendation
A
B
C
Best Available Supporting Evidence
Consistent and good quality patient-oriented evidence1
Inconsistent and/or limited quality patient-oriented evidence
Consensus, usual practice, opinion, disease-oriented2 evidence
or, case series
1
Patient-oriented evidence measures outcomes that matter to patients: morbidity, mortality,
symptom improvement, cost reduction and quality of life.
2
Disease-oriented evidence measures intermediate, physiologic, or surrogate end points that
may or may not reflect improvement in patient-oriented outcomes.
Reference
1. Ebell MH, Siwek J, Weiss BD, Woolf SH, et al. Strength of recommendation taxonomy
(SORT): A patient-centered approach to grading evidence in the medical literature. J Family
Practice 2004;53:111-20.