Systematic Reviews of Nonrandomized Clinical Studies in the Orthopaedic Literature

We systematically reviewed systematic reviews of surgical orthopaedic interventions published between 1996 and 2001 to document when and how nonrandomized studies were included. From more than 10,000 citations examined in various electronic databases, 58 orthopaedic systematic reviews were eligible for inclusion based on specific criteria. Thirty of these (52%) included nonrandomized studies, 15 of which found no randomized controlled trials. …