Background: Clinical practice is not always evidence-based and, therefore, may not optimise patient outcomes. Opinion leaders disseminating and implementing 'best evidence' is one innovative method that holds promise as a strategy to bridge evidence-practice gaps.
Objectives: To assess the effectiveness of the use of local opinion leaders in improving the behaviour of health care professionals and patient outcomes.
Search strategy: We searched MEDLINE, Health Star, SIGLE and the Cochrane Effective Practice and Organisation of Care Group Trials Register. We did not apply date restrictions to our search strategy. Searches were last updated in February 2005. In addition, we searched reference lists of all potential studies that were identified.
Selection criteria: Studies eligible for inclusion were randomized controlled trials that used objective measures of performance/provider behaviour and/or patient health outcomes.
Data collection and analysis: Two reviewers extracted data from each study and assessed its methodological quality. We calculated the absolute difference in the risk of 'non-compliance' with desired practice, adjusting for baseline levels of non-compliance where these data were available.
Main results: Twelve studies met our eligibility criteria. The adjusted absolute risk difference of non-compliance with desired practice varied from -6% (favouring control) to +25% (favouring opinion leader intervention). Overall, the median adjusted risk difference (ARD) was 0.10 representing a 10% absolute decrease in non-compliance in the intervention group.
Authors' conclusions: The use of local opinion leaders can successfully promote evidence-based practice. However the feasibility of its widespread use remains uncertain.