The quality of systematic reviews in dentistry.
DATA SOURCES: Sources of reviews were the Database of Reviews of Effectiveness (DARE) and completed systematic reviews registered by the Cochrane Oral Health Group in the Cochrane Library. STUDY SELECTION: All systematic reviews that examined the effectiveness of interventions for oral, dental and craniofacial disorders and diseases were eligible for inclusion. DATA EXTRACTION AND SYNTHESIS: A quality assessment checklist was completed for each study. RESULTS: A total of 115 studies were identified, of which 65 were relevant to the review. The area most frequently evaluated within the reviews was pain relief or prevention (20 out of 65, ie, 31%) followed by caries, and oral medicine. The quality assessment of the systematic reviews identified highlighted key areas where improvements could be made. One major weakness was that the search strategies employed in reviews were not always adequate: only 12 reviews (19%) demonstrated an attempt to identify all relevant studies. Other areas of weakness include the screening and quality assessment of primary studies, the pooling of data and examination of heterogeneity, and the interpretation of findings. CONCLUSIONS: The quality of systematic reviews in dentistry could be improved. If future clinical decisions are to be based upon systematic reviews, it is imperative that reviews address clinically-relevant, focused questions, and follow a transparent, well-designed protocol.