Search and selection methodology of systematic reviews in orthodontics (2000-2004)

Introduction: More systematic reviews related to orthodontic topics are published each year, although little has been done to evaluate their search and selection methodologies. Methods: Systematic reviews related to orthodontics published between January 1, 2000, and December 31, 2004, were searched for their use of multiple electronic databases and secondary searches. The search and selection methods of identified systematic reviews were evaluated against the Cochrane Handbook's guidelines. Results: Sixteen orthodontic systematic reviews were identified in this period. The percentage of reviews documenting and using each criterion of article searching has changed over the last 5 years, with no recognizable directional trend. On average, most systematic reviews documented their electronic search terms (88%) and inclusion-exclusion criteria (100%), and used secondary searching (75%). Many still failed to search more than MEDLINE (56%), failed to document the database names and search dates (37%), failed to document the search strategy (62%), did not use several reviewers for selecting studies (75%), and did not include all languages (81%). Conclusions: The methodology of systematic reviews in orthodontics is still limited, with key methodological components frequently absent or not appropriately described.