Levels of evidence backing the AAOS clinical practice guidelines

Purpose: The American Academy of Orthopaedic Surgeons produces clinical practice guidelines for the treatment of orthopedic injuries. We examined the strength of the evidence underlying these recommendations in order to answer the following questions: (1) Have AAOS work groups improved guideline creation practices to locate evidence to generate strong recommendations? (2) Is there variability in the available evidence based on anatomic site or stage of care? (3) Has the level of evidence supporting improved over time? Methods: Twenty-two current guidelines of the Academy were examined which yielded 408 individual recommendations. These recommendations were assigned one of five strength of evidence ratings (strong, moderate, limited, inconclusive, consensus) by the guideline panel, based on the availability and quality of the supporting evidence. From these guidelines, we extracted all of the recommendations and their corresponding evidence ratings. We then classified the recommendations by stage of care, year, and anatomical site. Results: The distribution of the levels of evidence was as follows: 77 (18.9%) were based on consensus; 53 (13.0%) were inconclusive; 93 (22.8%) were based on limited evidence; 112 (27.5%) were based on moderate evidence; and 73 were based on (17.9%) strong evidence. Strong strength of evidence was found in 45.2% of the recommendations for preventive/screening/diagnostic care, 41.1% of nonsurgical treatment, 45.1% of surgical treatment, 51.1% of rehabilitation/postoperative treatment, and 45.5% of the recommendations that had mixed stages of care. Inconclusive strength of evidence was found to be prevalent from 2009–2013, but was eliminated starting in 2014. Conclusions: Only 73 (17.9%) recommendations generated by the Academy in its 22 clinical practice guidelines are based on a “strong” strength of evidence. More robust research is needed in orthopedics to bolster confidence in the recommendations in future guideline updates.