Local opinion leaders: effects on professional practice and health care outcomes.

BACKGROUND: Both the theory of diffusion of innovations and the social influences model of behaviour change suggest that using local opinion leaders to transmit norms and model appropriate behaviour may improve health professional practice. OBJECTIVES: To assess the effects using local opinion leaders on the practice of health professionals or patient outcomes. SEARCH STRATEGY: We searched MEDLINE to May 1998, the Research and Development Resource Base in Continuing Medical Education, and reference lists of related systematic reviews and articles. SELECTION CRITERIA: Randomised trials of the use of local opinion leaders (defined as health professionals nominated by their colleagues as being educationally influential). The participants were health care professionals responsible for patient care. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed study quality. MAIN RESULTS: Eight studies were included involving more than 296 health professionals. A variety of patient problems were targeted, including acute myocardial infarction, cancer pain, osteoarthritis, rheumatoid arthritis, chronic lung disease, vaginal birth after caesarean section, labour and delivery, and urinary catheter care. Six of seven trials that measured health professional practice demonstrated some improvement for at least one outcome variable, and in two trials, the results were statistically significant and clinically important. In three trials that measured patient outcomes, only one achieved an impact upon practice that was of practical importance: local opinion leaders were effective in improving the rate of vaginal birth after previous caesarean section. REVIEWER'S CONCLUSIONS: Using local opinion leaders results in mixed effects on professional practice. However, it is not always clear what local opinion leaders do and replicable descriptions are needed. Further research is required to determine if opinion leaders can be identified and in which circumstances they are likely to influence the practice of their peers.