AFP uses the Strength-of-Recommendation Taxonomy (SORT),1 to label key recommendations in clinical review articles. In general, only key recommendations are given a Strength-of-Recommendation grade. Grades are assigned on the basis of the quality and consistency of available evidence. Table 1 shows the three grades recognized.
An alternative way to understand the significance of a strength-of-recommendation grade is through the algorithm generally followed by authors and editors in assigning grades based on a body of evidence (Figure 1). While this algorithm provides a general guideline, authors and editors may adjust the strength of recommendation based on the benefits, harms, and costs of the intervention being recommended.
|Strength of recommendation
|Basis for recommendation
|Consistent, good-quality patient-oriented evidence*
|Inconsistent or limited-quality patient-oriented evidence*
|Consensus, disease-oriented evidence,* usual practice, expert opinion, or case series for studies of diagnosis, treatment, prevention, or screening
|Level 1: good-quality, patient-oriented evidence
|Validated clinical decision rule
|SR/meta-analysis or RCTs with consistent findings
|SR/meta-analysis of good-quality cohort studies
|SR/meta-analysis of high-quality studies
|High-quality individual RCT†
|Prospective cohort study with good follow-up
|High-quality diagnostic cohort study*
|Level 2: limited-quality patient-oriented evidence
|Unvalidated clinical decision rule
|SR/meta-analysis of lower quality clinical trials or of studies with inconsistent findings
|SR/meta-analysis of lower quality cohort studies or with inconsistent results
|SR/meta-analysis of lower quality studies or studies with inconsistent findings
|Lower quality diagnostic cohort study or diagnostic case-control study
|Lower quality clinical trial
|Retrospective cohort study or prospective cohort study with poor follow-up
|Level 3: other evidence
|Consensus guidelines, extrapolations from bench research, usual practice, opinion, disease-oriented evidence (intermediate or physiologic outcomes only), or case series for studies of diagnosis, treatment, prevention, or screening
|Most studies found similar or at least coherent conclusions (coherence means that differences are explainable).
|If high-quality and up-to-date systematic reviews or meta-analyses exist, they support the recommendation.
|Considerable variation among study findings and lack of coherence
|If high-quality and up-to-date systematic reviews or meta-analyses exist, they do not find consistent evidence in favor of the recommendation.