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


Transferring evidence from research into practice: 4. Overcoming barriers to application

ACP J Club. 1997 May-Jun;126:A14. doi:10.7326/ACPJC-1997-126-3-A14

In the 3 preceding essays in this series (1-3), we described a path that leads from health care research evidence to evidence-based health care. The steps include getting the evidence straight, developing evidence-based clinical policy, and then applying the policy. In this editorial, we focus on the final step, applying evidence-based policy in the right way at the right place and time. As a precondition, application efforts are only justified if the evidence on which they are based is up to date and has been accurately incorporated and if the policy to be applied achieves a workable balance between both the evidence from research and the circumstances in which the evidence must be applied.

When we see patients, we are responsible for applying evidence and evidence-based clinical policies in the management of their clinical problems. But even when the evidence is strong and the clinical policy is sound, powerful impediments often bar our way. The 3 impediments that we will discuss here are mismatches between evidence and clinical circumstances, time pressures in clinical practice, and difficulties in acquiring new clinical skills (4). Recent, important advances in stroke care, which include the presence of stroke units in hospitals and carotid endarterectomy, serve to illustrate all 3 impediments.

Mismatches between evidence and clinical circumstances

Convincing evidence shows that stroke units reduce morbidity and mortality in acute stroke (5). Unfortunately, most hospitals do not currently have stroke units. As a result, even when we and our patients want the benefits that can be derived from intensive stroke care, we must either wait for the solution of complex and expensive local resource problems or become mired ourselves in the political, financial, and logistic frays that impede such changes.

Strong studies also show that carotid endarterectomy reduces the risk for major stroke and death among patients with symptomatic high-grade (6) but not moderate-grade symptomatic carotid stenosis (7). This evidence diverges from current practices. For example, half of primary care physicians in one study indicated that they would seldom or never refer their patients with transient ischemic attacks or partial hemispheric strokes for angiography or endarterectomy, and only 10% of them knew a critical factor in the success of the procedure: the perioperative complication rates of local surgeons (8). But such information is difficult if not impossible to come by in most settings. Ironically, the number of endarterectomies done for moderate-grade asymptomatic and symptomatic stenosis is rising despite the absence of evidence of benefit (9). Thus, the mismatch between evidence and practice cuts both ways for carotid endarterectomy—underuse for those who could benefit, and overuse for those who cannot.

The large variations in the practices of individual physicians are likely to have several causes, including real or perceived lack of applicability of the evidence to individual patients, lack of adequate local facilities, inadequacy of continuing education events and resources, and premature or inappropriate adoption of new practices without adequate evidence or awareness of applicable evidence. Unfortunately, evidence on how best to deal with these barriers is scant (health services researchers, please note!). Fortunately, there are validated approaches for overcoming at least some of these problems, as we discuss below.

Time pressures in clinical practice

We all know how pressed we are for time. Traditionally, it has taken considerable time to find, critically appraise, and assimilate evidence, and it takes time to identify and overcome the organizational barriers to application of evidence in clinical practice. Fortunately, the time barrier is being eroded, if not broken, by electronic access to high-quality evidence resources for which much of the appraisal and summarization have already been done (10-13). Even so, organizational barriers must often be overcome to deliver care quickly, as is needed to optimize benefits for many treatments.

The scarce time we salvage for acquiring new skills is often not well spent. Learning about new evidence and sensible policies is necessary, but information alone is clearly not sufficient to change our long-term behavior (14) and we need to take advantage of more effective forms of learning.

Overcoming difficulties in learning new “clinical” skills

We will close with some good news. 3 lines of evidence about changing our behavior that have emerged from randomized trials show ways that work. They clear up some myths about traditional continuing medical education (14), describe some effective computerized clinical decision supports (15), and summarize effective interventions that can help our patients follow the treatments we've negotiated with them (16).

Familiar approaches to keeping up to date, such as mailed information and didactic continuing education, are not very effective in changing our practice performance and our patients' outcomes (14). Thus, if the hard work involved in systematically summarizing evidence and creating clinically sensible policy is to benefit anyone, we need to harness other, more effective ways of bringing our clinical performance in line with the best evidence. Several options for helping us clinicians exist, including (singly or, better still, in combination) reminders, outreach visits, patient-mediated interventions, educational influentials (opinion leaders), practice audit with personalized feedback, and combinations of these interventions (14). The studies contain important information for all of us to heed in putting our scarce continuing education time to best use.

Computerized clinical decision support systems have been studied in several forms and settings, and randomized trials show that reminder systems that automatically match our patients' characteristics to recommendations can make us more effective in giving preventive and acute care and in calculating safe, effective doses for some toxic drugs (15).

Our patients often fail to follow the regimens we offer them and frequently drop out of care entirely, which severely undermines the effectiveness of the interventions we negotiate with them. Fortunately, recent overviews describe validated ways to help these patients stay in care through mail and telephone reminders as well as some more complex behavioral interventions (17). Counseling and written instructions have been shown to improve adherence to short-term treatments. More complicated interventions are needed to enhance adherence to longer-term treatments, including combinations of more convenient care, information, counseling, reminders, self-monitoring, reinforcement, and family therapy (16).

This brief summary hardly does justice to the extensive research in continuing education, quality improvement, computer-aided decision support and patient adherence, so we will revisit these topics in subsequent issues. In the meantime, we are attempting to apply the following recipe in our own practices. First, we've read the reviews of interventions cited below (14-17) and have tried to adopt the effective interventions that best suit our circumstances. Second, we look for continuing education activities that provide interactive rather than didactic opportunities to learn, with supervised rehearsal and practice if possible. We're doing our best to choose clinical topics for our continuing education that we feel least comfortable with, because it has been shown that we do well without much instruction in topics that we enjoy but learn and change more when we're instructed on topics that we usually avoid 18). Third, we've looked into computerized reminder systems and look forward to implementing some of them in our own practices. Finally, we're struggling to make our efforts count by insisting that all the new practices we learn about are rigorously based on evidence that their implementation does more good than harm.

Putting evidence to work in our practices not only helps our patients, but helps us and our profession. Being able to provide our patients with advice confidently based on current best evidence is very satisfying professionally. Being able to bring evidence to bear on the demands from politicians and administrators for cost control and quality improvement helps us to resist unwarranted pressures and to preserve our ability to do what's best for patients.

R. Brian Haynes
David L. Sackett
Gordon H. Guyatt
Deborah J. Cook
J.A. Muir Gray


1. Haynes RB, Sackett DL, Gray JA, Cook DJ, Guyatt GH.Transferring evidence from research into practice: 1. The role of clinical care research evidence in clinical decisions. ACP J Club. 1996 Nov-Dec;125:A14-6.

2. Haynes RB, Sackett DL, Gray JA, Cook DJ, Guyatt GH.Transferring evidence from research into practice: 2. Getting the evidence straight. ACP J Club. 1997 Jan-Feb;126;A14-6.

3. Gray JA, Haynes RB, Sackett DL, Cook DJ, Guyatt GH.Transferring evidence from research into practice: 3. Developing evidence-based clinical policy. ACP J Club. 1997 Mar-Apr;126;A14-6.

4. Haynes RB. Ann NY Acad Sci. 1993;703: 210-24.

5. Specialist inpatient stroke unit care reduces mortality and institutionalisation compared with general medical ward care. Evidence-Based Medicine. 1995 Nov-Dec;1:11.

6. Carotid endarterectomy reduced death and strokes in patients with ipsilateral high-grade stenosis and recent hemispheric transient ischemic attacks or nondisabling strokes. ACP J Club. 1991;121:34.

7. Endarterectomy was not effective for moderate symptomatic carotid stenosis. ACP J Club. 1996;125:29.

8. Goldstein LB, Bonito AJ, Matchar DB, Duncan PW, Samsa GP. Stroke. 1996;27:801-6.

9. Barnett HJ, Eliasziw M, Meldrum HE, Taylor DW. Neurology. 1996;46:603-8.

10. Sackett DL, Richardson SR, Rosenberg W, Haynes RB. Evidence-Based Medicine: How To Practice and Teach EBM. London: Churchill Livingstone, 1997.

11. Sackett DL.… so little time, and … Evidence-Based Medicine. 1997 Mar-Apr:2:39.

12. Announcing the arrival of Best Evidence. ACP J Club. 1997 Jan-Feb;126:A16.

13. The Cochrane Library [database on disk and CD-ROM]. The Cochrane Collaboration. Oxford: Update Software. Quarterly electronic publication.

14. Davis DA, Thomson MA, Oxman AD, Haynes RB. JAMA. 1995;274:700-5.

15. Johnston ME, Langton KB, Haynes RB, Mathieu A. Ann Intern Med. 1994;120: 135-42.

16. Haynes RB, McKibbon KA, Kanani R. Lancet. 1996;348:383-6.

17. Macharia WM, Leon G, Rowe BH, Stephenson BJ, Haynes RB. JAMA. 1992;267:1813-7.

18. Sibley JC, Sackett DL, Neufeld V, et al. N Engl J Med. 1982;306:511-5.