Effectiveness of the use of local opinion leaders to promote evidence-based practice and improving patient outcomes

Clinical practice is not always evidence-based and, therefore, may not optimise patient outcomes. Opinion leaders disseminating and implementing 'best evidence' is one method that holds promise as a strategy to bridge evidence-practice gaps. Opinion leaders are people who are seen as likeable, trustworthy and influential. Because of their influence, it is thought that they may be able to help and persuade healthcare providers to use evidence when treating and managing patients.

We searched the scientific literature for randomised controlled trials that evaluated the effectiveness of the use of opinion leaders to disseminate and implement evidence-based medicine. We found 18 trials involving more than 296 hospitals and 318 primary care practices. Most of the included studies had some methodological shortcomings. The effects of interventions varied across the 63 outcomes from 15% decrease in compliance to 72% increase in compliance with desired practice. The median adjusted RD for the main comparisons were: i) Five trials that compared opinion leaders alone to no intervention, +0.09; ii) Two trials that compared opinion leaders alone to a single intervention, +0.14; iii) Four trials that compared opinion leaders with one or more additional intervention(s) to the one or more additional intervention(s), +0.10 and iv) Ten trials that compared opinion leaders as part of multiple interventions to no intervention, +0.10. Overall, the median adjusted RD across all studies was +0.12 representing 12% absolute increase in compliance in the intervention group.

In a majority of studies the sociometric method was used to identify opinion leaders, while two studies used the informant method, but due to the few studies using this method we could not conclude whether the method of identification had any impact on the effectiveness of interventions.

Three studies used multidisciplinary teams to promote evidence-based practice. The median adjusted RD for these trials was +0.18 representing a 18% absolute increase in compliance in the intervention group. However, two of the trials involved multiple interventions, and therefore the effectiveness of opinion leader teams could not be distinguished.

The results of this review show that opinion leaders may promote evidence-based practice. These results are based on heterogeneous studies using a variety of different interventions, performed in a variety of different settings, and aiming at changing a number of different outcomes. In most of the included studies the role of the opinion leader was not clearly described (educational methods used, degree or frequency of involvement of opinion leaders), and it is therefore not possible to say what is the best way to optimise the effectiveness of opinion leaders.

Authors' conclusions: 

Opinion leaders alone or in combination with other interventions may successfully promote evidence-based practice, but effectiveness varies both within and between studies. These results are based on heterogeneous studies differing in terms of type of intervention, setting, and outcomes measured. In most of the studies the role of the opinion leader was not clearly described, and it is therefore not possible to say what the best way is to optimise the effectiveness of opinion leaders.

Read the full abstract...
Background: 

Clinical practice is not always evidence-based and, therefore, may not optimise patient outcomes. Opinion leaders disseminating and implementing 'best evidence' is one 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 professional practice and patient outcomes.

Search strategy: 

We searched Cochrane EPOC Group Trials Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, HMIC, Science Citation Index, Social Science Citation Index, ISI Conference Proceedings and World Cat Dissertations up to 5 May 2009. In addition, we searched reference lists of included articles.

Selection criteria: 

Studies eligible for inclusion were randomised controlled trials investigating the effectiveness of using opinion leaders to disseminate evidence-based practice and reporting objective measures of professional performance and/or health outcomes.

Data collection and analysis: 

Two review authors independently extracted data from each study and assessed its risk of bias. For each trial, we calculated the median risk difference (RD) for compliance with desired practice, adjusting for baseline where data were available. We reported the median adjusted RD for each of the main comparisons.

Main results: 

We included 18 studies involving more than 296 hospitals and 318 PCPs. Fifteen studies (18 comparisons) contributed to the calculations of the median adjusted RD for the main comparisons. The effects of interventions varied across the 63 outcomes from 15% decrease in compliance to 72% increase in compliance with desired practice. The median adjusted RD for the main comparisons were: i) Opinion leaders compared to no intervention, +0.09; ii) Opinion leaders alone compared to a single intervention, +0.14; iii) Opinion leaders with one or more additional intervention(s) compared to the one or more additional intervention(s), +0.10; iv) Opinion leaders as part of multiple interventions compared to no intervention, +0.10. Overall, across all 18 studies the median adjusted RD was +0.12 representing a 12% absolute increase in compliance in the intervention group.