Person:

Guadagnoli, Edward

Background: Evidence-based guidelines for the treatment of patients with acute myocardial infarction (AMI) have been published and disseminated by the American College of Cardiology and the American Heart Association. Few studies have examined the rates of adherence to these guidelines in eligible populations and the influence of age and gender on highly effective AMI treatments in community hospital settings.

Methods: Medical records of 2409 individuals admitted to 37 Minnesota hospitals between October 1992 and July 1993 for AMI, suspected AMI, or rule-out AMI, and meeting electrocardiographic, laboratory, and clinical criteria suggestive of AMI were reviewed to determine the proportion of eligible patients who received thrombolytic, β-blocker, aspirin, and lidocaine hydrochloride therapy. The effects of patient age, gender, and hospital teaching status on the use of these treatments were estimated using logistic regression models.

Results: Eligibility for treatment ranged from 68% (n=1627) for aspirin therapy, 38% (n=906) for lidocaine therapy, and 30% (n=734) for thrombolytic therapy to 19% (n=447) for β-blocker therapy. Seventy-two percent of patients eligible to receive a thrombolytic agent received this therapy; 53% received β-blockers; 81% received aspirin; and 88% received lidocaine. Among patients ineligible for lidocaine therapy (n=1503), 20% received this agent. Use of study drugs was lower among eligible elderly patients, especially those older than 74 years (thrombolytic agent: odds ratio, 0.2; 95% confidence interval, 0.1 to 0.4; aspirin: odds ratio, 0.4, 95% confidence interval, 0.3 to 0.6;β-blocker: odds ratio, 0.4; 95% confidence interval, 0.2 to 0.8). Female gender was associated with lower levels of aspirin use among eligible patients (odds ratio, 0.7; 95% confidence interval, 0.6 to 0.9); and there was a trend toward lower levels of β-blocker and thrombolytic use among eligible women.

Conclusions: Use of lifesaving therapies for eligible patients with AMI is higher than previously reported, particularly for aspirin and thrombolytic use in nonelderly patients. Lidocaine is still used inappropriately in a substantial proportion of patients with AMI. Increased adherence to AMI treatment guidelines is required for elderly patients and women.(Arch Intern Med. 1996;156:799-805)

Background The rapid expansion of managed care in the United States has increased debate regarding the appropriate mix of generalist and specialist involvement in medical care.

Objective To compare the quality of medical care when generalists and cardiologists work separately or together in the management of patients with acute myocardial infarction (AMI).

Methods We reviewed the charts of 1716 patients with AMI treated at 22 Minnesota hospitals between 1992 and 1993. Patients eligible for thrombolytic aspirin, β-blockers, and lidocaine therapy were identified using criteria from the 1991 American College of Cardiology guidelines for the management of AMI. We compared the use of these drugs among eligible patients whose attending physician was a generalist with no cardiologist input, a generalist with a cardiologist consultation, and a cardiologist alone.

Results Patients cared for by a cardiologist alone were younger, presented earlier to the hospital, were more likely to be male, had less severe comorbidity, and were more likely to have an ST elevation of 1 mm or more than generalists' patients. Controlling for these differences, there was no variation in the use of effective agents between patients cared for by a cardiologist attending physician and a generalist with a consultation by a cardiologist. However, there was a consistent trend toward increased use of aspirin, thrombolytics, and β-blockers in these patients compared with those with a generalist attending physician only (P<.05 for β-blockers only). Differences between groups in the use of lidocaine were not statistically significant. The adjusted probabilities of use of thrombolytics for consultative care and cardiologist attending physicians were 0.73 for both. Corresponding probabilities were 0.86 and 0.85 for aspirin and 0.59 and 0.57 for β-blockers, respectively.

Conclusions For patients with AMI, consultation between generalists and specialists may improve the quality of care. Recent policy debates that have focused solely on access to specialists have ignored the important issue of coordination of care between generalist and specialist physicians. In hospitals where cardiology services are available, generalists may be caring for patients with AMI who are older and more frail. Future research and policy analyses should examine whether this pattern of selective referral is true for other medical conditions.

THE RAPID expansion of managed care in the United States has increased public and scientific debate regarding the appropriate mix of generalist and specialist involvement in medical care. Previous research suggests that cardiologists have better knowledge than generalists concerning efficacious therapies in the treatment of acute myocardial infarction (AMI).1 However, previous studies2 also suggest that there is little relationship between knowledge or self-reported practice and actual behavior. Despite intense controversy, few studies3 exist comparing the care provided to comparable patients by generalists and specialists.

The focus on comparative performance of generalists and specialists ignores opportunities for sharing of knowledge and experience through formal and informal consultation. In 1 study,4 the quality of psychoactive drug prescribing in nursing homes was highest among generalists who reported frequent consultations with psychiatrists. A recent study5 of a US health maintenance organization showed that an intervention fostering collaborative care between generalists and psychiatrists improved adherence to antidepressant regimens, patient satisfaction, and other outcomes in patients with major depression.

In contrast to previous studies1,6,7 that used survey data to measure differences between generalist and specialist care, we investigated differences in quality of care actually provided to patients with AMI when generalists and cardiologists work separately and in consultation. Quality of care was defined as care consistent with nationally recognized evidence-based practice guidelines. Specifically, we examined the use of drugs known to reduce morbidity and mortality in eligible patients (aspirin, thrombolytics, and β-blockers),8- 11 and nonindicated use of lidocaine, which may cause increased mortality.12 We compared use of these drugs among patients whose attending physician was (1) a generalist with no cardiologist input, (2) a generalist with cardiologist consultation, and (3) a cardiologist.

Context.— The effectiveness of recruiting local medical opinion leaders to improve quality of care is poorly understood.

Objective.— To evaluate a guideline-implementation intervention of clinician education by local opinion leaders and performance feedback to (1) increase use of lifesaving drugs (aspirin and thrombolytics in eligible elderly patients, β-blockers in all eligible patients) for acute myocardial infarction (AMI), and (2) decrease use of a potentially harmful therapy (prophylactic lidocaine).

Design.— Randomized controlled trial with hospital as the unit of randomization, intervention, and analysis.

Setting.— Thirty-seven community hospitals in Minnesota.

Patients.— All patients with AMI admitted to study hospitals over 10 months before (1992-1993, N=2409) or after (1995-1996, N=2938) the intervention.

Intervention.— Using a validated survey, we identified opinion leaders at 20 experimental hospitals who influenced peers through small and large group discussions, informal consultations, and revisions of protocols and clinical pathways. They focused on (1) evidence (drug efficacy), (2) comparative performance, and (3) barriers to change. Control hospitals received mailed performance feedback.

Main Outcome Measures.— Hospital-specific changes before and after the intervention in the proportion of eligible patients receiving each study drug.

Results.— Among experimental hospitals, the median change in the proportion of eligible elderly patients receiving aspirin was +0.13 (17% increase from 0.77 at baseline), compared with a change of −0.03 at control hospitals (P=.04). For β-blockers, the respective changes were +0.31 (63% increase from 0.49 at baseline) vs +0.18 (30% increase from baseline) for controls (P=.02). Lidocaine use declined by about 50% in both groups. The intervention did not increase thrombolysis in the elderly (from 0.73 at baseline), but nearly two thirds of eligible nonrecipients were older than 85 years, had severe comorbidities, or presented after at least 6 hours.

Conclusions.— Working with opinion leaders and providing performance feedback can accelerate adoption of some beneficial AMI therapies (eg, aspirin, β-blockers). Secular changes in knowledge and hospital protocols may extinguish outdated practices (eg, prophylactic lidocaine). However, it is more difficult to increase use of effective but riskier treatments (eg, thrombolysis) for frail elderly patients.

THE INFLUENCE OF local medical opinion leaders in the diffusion and adoption of new medical treatments has been recognized for almost half a century.1,2 Opinion leaders are not necessarily innovators or authority figures, but are trusted by their colleagues to evaluate new information and assess the value of new medical practices in the context of local group norms3; are approached frequently for clinical advice; have good listening skills4; and are perceived as clinically competent and caring.5 Many researchers and policymakers advocate recruiting opinion leaders in ongoing quality improvement efforts, in part because of the potential efficiency of capitalizing on local volunteers skilled in changing practice patterns.6 Yet, evidence supporting such interventions is limited,4,7,8 including only 1 randomized controlled trial (RCT) that enlisted local opinion leaders to reduce unnecessary cesarean deliveries in Canada.4 No well-controlled study has examined the effectiveness of recruiting opinion leaders to influence the adoption of underused, lifesaving interventions for major acute illnesses, such as acute myocardial infarction (AMI).

The selection of treatments for AMI patients represents one of the most critical decisions in medical practice.9 Coronary heart disease is the leading cause of death in the United States.10 Large RCTs and national guidelines strongly support the early administration of aspirin, β-blockers, and thrombolytic agents for AMI because they substantially reduce mortality and morbidity in eligible patients.9,11- 18 However, a meta-analysis of 14 RCTs of lidocaine prophylaxis to reduce ventricular fibrillation during AMI indicates that this practice may lead to increased mortality, especially in uncomplicated MI.19 The national guidelines also recommend avoidance of lidocaine prophylaxis.17,18 Yet, recent studies of actual practice have found substantial nonadherence to these recommendations, resulting in potentially avoidable morbidity and mortality.20,21 Our previous report of baseline data at the 37 hospitals participating in this study indicated that only 53% of eligible patients received β-blockers.21 Although aspirin use and thrombolysis were high (87% and 81%, respectively) among eligible nonelderly patients, only 76% and 69% of eligible elderly patients (aged 65 years or older) received aspirin and thrombolytic agents, respectively. About 20% of patients received prophylactic lidocaine.

In this article we report the results of a large statewide RCT that combined identification and involvement of local opinion leaders with performance feedback to improve quality of care for AMI. Specifically, we sought to increase adherence to the national (American College of Cardiology/American Heart Association [ACC/AHA]) guidelines recommending (1) increased use of highly effective drugs for eligible AMI patients, ie, β-blockers in all patients and aspirin and thrombolysis in the elderly, and (2) reduced use of an ineffective treatment, ie, prophylactic lidocaine.