Current issues of ACP Journal Club are published in Annals of Internal Medicine

Quality Improvement

Local opinion leaders increased the appropriate use of aspirin and β-blockers in patients hospitalized with acute MI

ACP J Club. 1998 Nov-Dec; 129:78. doi:10.7326/ACPJC-1998-129-3-078

Source Citation

Soumerai SB, McLaughlin TJ, Gurwitz JH, et al. Effect of local medical opinion leaders on quality of care for acute myocardial infarction. A randomized controlled trial. JAMA. 1998 May 6;279:1358-63.



Can a guideline-based, multifaceted intervention delivered by a local opinion leader increase appropriate use and decrease inappropriate use of lifesaving drugs in patients hospitalized with acute myocardial infarction (MI)?


Randomized controlled trial.


37 community hospitals in Minnesota, United States.


All patients hospitalized with confirmed acute MI for 10 months before (n = 2409) and after (n = 2938) the study intervention.


20 hospitals were allocated to the opinion-leader group, and 17 were allocated to be control hospitals. For each study hospital, an opinion leader was nominated by physicians who worked at that hospital. These leaders met as a group for 1 day to discuss Minnesota Clinical Comparison and Assessment Program (MCCAP) Acute Myocardial Infarction guidelines, supporting evidence, feedback on drug use, and barriers to change. All leaders were given slides, administrative support, and brochures and were encouraged to implement the MCCAP guidelines in their own hospitals. Control hospitals received mailed feedback on drug use.

Main outcome measures

Hospital-specific changes in appropriate use of oral aspirin and thrombolytic agents in eligible elderly patients, appropriate use of β-blockers in all eligible patients, and inappropriate use of prophylactic lidocaine for eligible patients with acute MI, according to the MCCAP guidelines. All categories for each hospital had to have had ≥ 7 patients before and after the intervention for analysis to be done.

Main results

After the study, the median proportion of eligible elderly patients receiving aspirin had increased from 0.77 to 0.90 in study hospitals and had decreased from 0.80 to 0.77 in control hospitals (P = 0.04 for the difference between the 2 groups). β-blocker use showed similar results: The median proportion of patients receiving β-blockers increased from 0.49 to 0.80 for study hospitals and from 0.60 to 0.78 for control hospitals (P = 0.02 for the difference). No change in inappropriate lidocaine use (P > 0.2) or appropriate use of thrombolytic agents was shown (according to limited data). Most eligible patients who did not receive thrombolytic agents were > 85 years of age, had severe comorbid conditions, and presented ≥ 6 hours after symptom onset.


Local opinion leaders increased the appropriate use of oral aspirin and β-blockers in patients hospitalized with acute myocardial infarction.

Sources of funding: Agency for Health Care Policy and Research; Healthcare Education and Research Foundation; Harvard Pilgrim Health Care Foundation.

For correspondence: Dr. S.B. Soumerai, Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Health Care, 126 Brookline Avenue, Suite 200, Boston, MA 02215, USA. FAX 617-859-8112.


Should policy makers with responsibility for professional or quality improvement consider recruiting opinion leaders to influence management of MI or other clinical activities in different settings? The answer from this study is unclear. The intervention used was based on a previously established "real world" quality-improvement collaboration that may have sensitized the targeted clinicians in a way that is not generalizable to other settings. Further, the study had mixed effects. The lack of effect of the intervention on use of thrombolytic agents in the elderly is attributed to the high baseline use by eligible recipients and the characteristics of eligible nonrecipients; however, the inter-vention may have been less effective at changing the more complex and risky clinical processes involved in the provision of thrombolysis. The lack of an observed effect is attributed to the high baseline use in eligible patients and the characteristics of eligible patients who did not receive it; however, the intervention on use of lidocaine could have been caused by the effectiveness of the feedback intervention in the "control" hospitals or by a secular trend.

Systematic reviews of rigorous evaluations of implementation strategies provide the best evidence for decisions about continuing professional education and quality improvement activities. A systematic review by Thomson and colleagues (1) of the effectiveness of opinion leaders identified 8 randomized trials (including this study) and concluded that "the use of local opinion leaders resulted in mixed effects." We currently have insufficient information about the effectiveness and efficiency of opinion leaders compared with other implementation strategies and about which factors influence the effectiveness of the opinion-leader intervention. Policy makers should be cautious in using opinion leaders as a sole intervention.

Jeremy M. Grimshaw, MBChB, PhD
University of AberdeenAberdeen, Scotland, UK


1. Thomson MA, Oxman AD, Haynes RB, et al. Local opinion leaders to improve health professional practice and health care outcomes. Cochrane Review, latest version in press, 1998. In: The Cochrane Library.Oxford: Update Software.