What does evidence-based practice mean? How does a surgeon practice evidence-based orthopaedics?
Although surgeons have always used evidence obtained from the surgical literature to make clinical decisions, evidence-based practice means using the “best available evidence” in caring for patients.
Best available evidence comes from well-designed, appropriately-conducted studies. Studies, however, vary in quality. Levels of Evidence are one measure of study quality. Are Levels of Evidence a perfect measure of study quality? No! Is the evaluation of a study more complicated than can be provided by a simple Levels of Evidence rating? Yes!
Surgeons intuitively recognize that randomized studies are better than non-randomized studies; that prospective studies are better than retrospective studies; and that controlled studies are better than non-controlled studies. This is the essence of the Levels of Evidence system. Levels of evidence are a quick way for surgeons to appraise the quality of an article. For example, published, peer-reviewed Level I articles relevant to a surgeon’s practice require an in-depth appraisal of a quality randomized controlled trial—a good level of evidence that may prompt a surgeon to change his or her practice.
Levels of evidence have uses, including the following:
- To monitor trends in the quality of the surgical literature
- To help surgeons understand study quality
- To provide an impetus for surgeons to improve the quality of their own studies.
- To provide a language for surgeons to discuss study quality when debating treatment decisions.
- To rate the quality of articles in orthopaedic journals and to rate the quality of abstracts submitted to national meetings.
Grades of recommendation
Levels of evidence are also used in Grades of Recommendation. Surgeons understand that a single study, no matter how well done, must be interpreted in the context of all relevant studies. A summary of the entire literature is provided by Grades of Recommendation.
For example, high-quality Level I evidence providing consistent treatment recommendations are assigned a Grade A recommendation; surgeons would have to think long and hard not to adopt a Grade A recommendation into their practice. Treatment recommendations with poor evidence quality (Levels IV and V) or conflicting evidence would earn a Grade C; those with insufficient evidence to make a recommendation would be assigned Grade I.
In summary, levels of evidence and grades of recommendations are simple, intuitive tools designed to help you practice evidence-based orthopaedics.
James Wright, MD is chief of surgery at the Hospital for Sick Children in Toronto, Canada, and a member of the AAOS Evidence-Based Practice Committee.