Extract
Evidence-based medicine uses the best available evidence to make decisions
with patients. The highest-quality evidence is well-designed randomized
trials. The most compelling example of the power of trials comes from
pediatric oncology. The improvement in the survival rate of children with
cancer from 10% to 90% has been attributed almost exclusively to multiple
randomized trials1.
Since January 2003, every clinical article published in The Journal of
Bone and Joint Surgery has been assigned a level-of-evidence
rating2. Levels of
evidence provide a concise and simple appraisal of study quality. The essence
of levels of evidence is that, in general, controlled studies are better than
uncontrolled studies, prospective studies are better than retrospective
studies, and randomized studies are better than nonrandomized studies. Levels
of evidence have multiple purposes. First, levels of evidence provide the
readers of The Journal with a rapid appraisal of study quality.
Although a complete critical appraisal is required to determine study
quality3, readers
generally find higher levels of evidence more compelling. Second, levels of
evidence for multiple studies evaluating a clinical question can be summarized
as a "grade of recommendation." Grades of recommendations, such as
A, B, C, or I, provide an overall appraisal of the quality of literature for
or against a treatment
recommendation4.
Third, levels of evidence can be used to develop practice guidelines and
performance measures. In an era of pay-for-performance, whereby evidence-based
interventions receive higher
reimbursement5,6,
understanding levels of evidence is important for surgeons.