Evidence-Based Medicine and Practice Guidelines - An Overview

Steven H.Woolf, MD, MPH, Department of Family Practice, Medical College of Virginia - Virginia Commonwealth University, Fairfax, Virginia.

Cancer Control. 2000;7(4) 

In This Article

Limitations of Evidence-Based Practice Guidelines

Evidence-based practice guidelines, like all guidelines, can be flawed, advocating interventions that are not in the best interest of patients. [23] Sometimes the errors stem from limitations in the science itself, such as lack of data or poor generalizability. Sometimes errors occur when panel members reach invalid conclusions in translating science into policy. Biases or conflicts of interest among panel members, often exacerbated when outspoken individuals dominate the process, can produce different recommendations than the data support. Recommendations that do not give guidance on individualization or that reduce complex decisions into simplistic algorithms may be overly rigid and may result in more harm than good.

Practice guidelines can have adverse implications for clinicians, especially if they are rigidly enforced by payers, managers, or malpractice courts. They can have adverse policy implications for society if they increase the costs of care, decrease equity, or divert resources from more effective health care interventions.

A fundamental limitation of practice guidelines is that they often do not change practice behavior. Most studies indicate that passive dissemination of guidelines, such as publishing them in a medical journal, is ineffective in changing behavior. [24] Guidelines have been shown to be effective in changing practice patterns when they are accompanied by active implementation strategies, such as standing orders, reminder systems, academic detailing, audit, and feedback.

That physicians do not always counsel patients to stop smoking, do not always order screening mammograms when women need them, do not prescribe angiotensin-converting enzyme inhibitors for all patients with congestive heart failure -- despite guidelines from multiple organizations recommending these practices -- emphasizes the barriers that physicians face in changing behavior. [25] Beyond knowing what to do, clinicians also encounter attitudinal barriers in accepting the validity of recommendations, implementation barriers in opera-tionalizing recommendations in practice, and reinforcement barriers in maintaining a commitment to the intervention over time. [26] That a guideline recommends a service matters little if the clinician disputes it, cannot provide it (due to lack of time, equipment, or support from the health care system), or forgets that it is indicated.

The new frontier in EBM lies in developing effective strategies for translating evidence into practice. The most promising approaches tailor implementation strategies to the type of barriers involved, eg, local opinion leaders and academic detailing when attitudes are the obstacle, changing office operations, redesigning order forms, skill building, decision support tools to enhance implementation, and computerized reminder systems and other prompts to provide reinforcement. [27] These measures, when used to apply the growing wealth of data from clinical research, are most likely to fulfil the promise of EBM to improve the efficacy and equity of health care.