Learning in practice

Efficacy of case method learning in general practice for secondary prevention in patients with coronary artery disease: randomised controlled study

Anna Kiessling, head of the centre for clinical education ^a, Peter Henriksson, professor of internal medicine ^b. 

^a Centre for Clinical Education, Danderyd University Hospital and Karolinska Institute, SE-182 88 Stockholm, Sweden, ^b Department of Medicine, Karolinska Institute at Danderyd University Hospital, SE-182 88 Stockholm, Sweden

Correspondence to: P Henriksson Peter.Henriksson{at}med.ds.sll.se

	Abstract

Top Abstract Introduction Methods Results Discussion References

Objective: To study the efficacy of case method learning, for general practitioners, on patients' lipid concentrations in the secondary prevention of coronary artery disease.
Design: Prospective controlled trial.
Setting: Södertälje, Stockholm County, Sweden.
Participants: 255 consecutive patients with coronary artery disease.
Intervention: Guidelines were mailed to all general practitioners (n=54) and presented at a common lecture. General practitioners who were randomised to the intervention group participated in recurrent case method learning dialogues at their primary healthcare centres during a two year period. A locally well known cardiologist served as a facilitator.
Main outcome measure: Concentration of low density lipoprotein cholesterol at baseline and after two years. Analysis according to intention to treat (intervention and control groups (n=88)) was based on group affiliation at baseline.
Results: Low density lipoprotein cholesterol was reduced by 0.5 mmol/l (95% confidence interval 0.2 to 0.8 mmol/l) (9.3% (2.9% to 15.8%)) from baseline in patients in the intervention group and by 0.5 (0.1 to 0.9) mmol/l compared with controls (P<0.05). No change occurred in the control group (0.0 (0.2 to 0.2) mmol/l). Low density lipoprotein cholesterol decreased by 0.6 (0.4 to 0.8) mmol/l in a group of patients who received specialist care.
Conclusion: Case method learning resulted in a lowering of low density lipoprotein cholesterol in the primary care patients with coronary artery disease comparable to that achieved at a specialist clinic. Conventional presentation of practice guidelines had no effect.

	Introduction

Top Abstract Introduction Methods Results Discussion References

Lipid lowering was shown to be efficacious in patients with coronary artery disease in 1994.¹ Despite this, a gap exists between what is achieved in clinical practice and what should be aimed for according to scientific evidence based therapeutic goals.² Practice guidelines have been proposed as a means to decrease such gaps,³ but their effects have been limited.⁴

Clearly something more than just writing and distributing practice guidelines has to be done to increase knowledge and change the attitudes and performance of physicians. Practice guidelines tell you what to do but seldom how and when to do it. Furthermore, the context and content of a consultation in daily clinical practice is unstructured, unlike the strictly structured situation when a patient is enrolled in a clinical trial.⁵ The frames of clinical practice decisions will thus vary from patient to patient; framing has been recognised to have a great impact on the psychology of choice.⁶ A learning method suited to supporting and improving the complex clinical decision making process is needed. ^{7 8} Case method learning seemed to us to be an attractive method well suited to improving clinical practice. ^{9 10} A case is a description of an actual situation, commonly involving a decision, a challenge, an opportunity, or a problem faced by a person (or people) in an organisation. The case allows the learner to step figuratively into the position of a particular decision maker. ^{9 10}

Our aim was to assess whether case method learning had an effect on the cholesterol concentrations of general practitioners' patients with coronary artery disease and whether such an effect exceeded that of conventional introduction of practice guidelines. A secondary aim was to compare the effect of the intervention with what was concurrently achieved at a specialist clinic.

	Methods

Top Abstract Introduction Methods Results Discussion References

Study design
The aim was to study the efficacy of case method learning in general practice, on an end point at patient level, compared with the effect of distribution of guidelines and of specialist care. The local ethics committee of Karolinska Institute approved the study. Patients were unselected and had a diagnosis of coronary artery disease (see bmj.com for details). We asked patients who met the inclusion criteria for the name of the physician responsible for their care. We assigned patients who indicated a specialist physician (specialist in cardiology or internal medicine at the hospital or in private practice) to the "specialist" group (n=167) for study purposes. We studied the remaining patients (n=88) in the "control" or "intervention" group, according to which group their responsible general practitioner's primary healthcare centre was subsequently randomised into (see bmj.com). The characteristics of the two groups did not differ at baseline (tables A and B on bmj.com).

The next step was to develop the first local practice guidelines on secondary prevention of coronary artery disease in this part of Stockholm County. We did this immediately after the presentation of the results of the landmark Scandinavian simvastatin survival study.¹ The guidelines were presented and distributed at a local lecture (February 1995) for all general practitioners and specialists in the catchment area. A personal letter accompanying the practice guidelines was distributed after the meeting to all relevant physicians in the catchment area.

We randomised the two primary healthcare centre clusters into control and intervention groups, after checking for balance between both patients and physicians. We offered the general practitioners in the intervention group case method learning seminars at their own primary healthcare centre. All the general practitioners accepted the invitation. We held three to four seminars at each primary healthcare centre during the two year study period. Four to seven general practitioners and one facilitator participated on each occasion (attendance rate >82%). Each seminar lasted one hour. The seminars were based on a slightly modified case method learning technique. ^{9 10}

During the study five patients died, three had to be excluded owing to other serious disease, eight moved out of the district, and 19 refused to participate. This resulted in 220 (86%) patients completing the two year study period (April 1997).

At the end of the study we distributed a questionnaire to all general practitioners. It included questions about knowledge and relevance of scientific evidence and practice guidelines and satisfaction with the collaboration with the local hospital.

A research nurse handled all the research protocols and contacts with the patients. She was completely blinded as to which group an individual patient belonged to. She had no contacts with the general practitioners. The general practitioners had no knowledge that they were participating in a studythis was to avoid expectancy and attention (Hawthorne) effects.¹¹ We did not break the code until all databases were completed and the statistical analysis had been performed.

Educational intervention
A case is a description of a defined critical situation related to the real context of a general practitioner and involving a decision. It could be about an authentic patient or a defined critical situation concerning aspects of secondary prevention in daily clinical practice and involving a decision. A case in case method learning includes analytical, conceptual, and presentation dimensions.¹⁰ These dimensions could be divided into three levels of difficulty. Cases in clinical practice are all complex in the analytical and conceptual dimensions. There is no given obvious decision, and the sessions require that the participants have an extensive amount of knowledge and skills not supplied in the case. We kept the cases short (and well organised in the presentation dimension) because most general practitioners do not have time to prepare a case in a more traditional sense. This permitted concentration on the complex conceptual and analytical dimensions. The seminars started with the presentation of a case followed by an interactive dialogue between the participants. Active problem solving, defining, and valuing decision alternatives followed. A facilitatora locally well known cardiologistled the group in the interactive analytical discussion of the pros and cons and the feasibility of different potential solutions.

The figure shows a schematic cause-effect diagram of the clinical decision making process. In short, the process starts with the scientific evidence based practice guideline (what) and has to integrate individual components of the concrete and abstract frameworks of the physician and patient. The final result should be a decision to recommend or advise against an investigation, treatment, or motivational procedure for the patient. The physician's task becomes really complex when the clear structure of the practice guideline needs to be fitted into the complex world of the patient and physician.

View larger version (9K): [in this window] [in a new window]   Cause-effect diagram illustrating the clinical decision making process integrating scientific evidence (what) with the concrete and abstract components of clinical practice

The case method sessions included discussions of contextfor example, working conditions, family situation, lifestyle, economical constraints, and social and cultural settings of both the patient and the physician. However, the most important components were abstract in nature and included the values, attitudes, beliefs, emotions, motivation, knowledge, communicative capability, and sense of coherence of both the physician and the patient.¹² The decision also included ethical aspects. Urgency and timing (when) and practical aspects (how) were subsequently discussed and analysed. The final result should be a decision. See bmj.com for a presentation of a case with examples of aspects to be discussed.

Statistical methods
The primary effect variable of the study was change in low density lipoprotein cholesterol concentration in the intervention group compared with the control group. We analysed the data according to intention to treat, depending on which group of primary healthcare centres the physician responsible for patient care belonged to at the initiation of the study, irrespective of any change during the study. To check for robustness of results in this experimental study we used analysis of variance, analysis of covariance, and nested design. We used the non-parametric Mann-Whitney U test for the ordinal data of the questionnaires. We used Statistica 6.0 (StatSoft, Tulsa, OK, USA) for statistical analysis. We present the results as means and 95% confidence intervals or medians and quartiles.

	Results

Top Abstract Introduction Methods Results Discussion References

As shown in table 1, low density lipoprotein cholesterol concentration decreased from 4.2 (95% confidence interval 4.0 to 4.5) mmol/l to 3.7 (3.4 to 4.0) mmol/l in the intervention groupa 9.3% (2.9% to 15.8%) change. We found no change in the control group. In the specialist group low density lipoprotein cholesterol concentration decreased from 4.3 (4.1 to 4.4) mmol/l to 3.6 (3.4 to 3.8) mmol/la 12.6% (9.1% to 16.1%) change. Low density lipoprotein cholesterol concentration after two years was 0.5 (0.1 to 0.9) mmol/l lower (effect size 0.56) in the intervention group than in the control group (P<0.05).

General practitioners in the intervention and control groups did not differ in perceived knowledge and attitudes about secondary prevention at baseline. As shown in table 2, the general practitioners in the intervention group rated a higher perceived knowledge (P=0.007) and relevance (P=0.045) of scientific evidence and practice guidelines than controls after two years. Furthermore, we noted a higher satisfaction with the cooperation with the local hospital (P=0.004) concerning practice guidelines and policies.

	Discussion

Top Abstract Introduction Methods Results Discussion References

Case method learning for general practitioners resulted in a decrease in their patients' low density lipoprotein cholesterol concentrations to a degree that, according to current knowledge, should decrease mortality and morbidity in coronary artery disease.¹ Increases also occurred in the general practitioners' perceived knowledge of scientific evidence relating to secondary prevention in patients with coronary artery disease and their satisfaction with the collaboration with the local hospital.

Several explanations have been offered for the inefficiency of practice guidelines. ^{4 8 13-16} One is that practice guidelines are not written for practising physicians but focus on scientific knowledge.¹⁷ In-depth interviews indicate that personal experience or the advice and recommendations of colleagues are the most important factors determining attitudes and behaviour.¹⁸ Some authors also claim that physicians tend to disagree or distrust guidelines written by experts.^19-21 Specialists are more influenced by medical journals and scientific conferences, whereas general practitioners are more influenced by medical newspapers and postgraduate meetings.¹⁹ Methods of changing physicians' practices have been reviewed. ^{14 21-23} We consider that crucial components in our intervention are the focus on the physicians' own clinical practice, the small groups, the location of the seminars at their own practice, the recurrent intervention, and that the opinion leader was just a leader of the dialogues and not a lecturer. We used case method learning because this technique focuses on decision making and is interactive. ^{9 10 24} A review of another learning techniqueproblem based learningfound only limited evidence of effects.²⁵ The focus on decisions in the case method and our findings should justify its further use in interventions aimed at change in clinical performance.

A difference between clinical trials and clinical practice is that patients in studies are often highly selected. A strength of our study is that the patients are consecutivethat is, they are completely unselected. A weakness inherent in pedagogical interventions and in our study is the impossibility of separating the effect of the method from that of the tutor. However, a tutor is an essential part of most learning techniques and has to be trained and fit for the role.

The results concerning lipid lowering in patients treated by specialists is in line with what would be expected.¹ That patients treated by general practitioners in the control group had no decrease of their lipid concentrations despite publication of firm scientific evidence and presentation of local practice guidelines is, however, disconcerting. An explanation could be that patients with coronary artery disease represent only a minority of patients treated at a generalist practice as opposed to a majority at a specialist clinic. Generalists are faced with the difficult task of ensuring they are updated on scientific evidence relating to all the different diseases of their patients.¹⁷ However, a positive aspect of our study is that a mere three to four hours spent during a two year period seem to improve the quality of care of a particular patient group to a level similar to that achieved at a specialist clinic. Because of the broad spectrum of diseases in primary care, a high grade of time efficiency has to be a prerequisite. This seems to be fulfilled by the case method of learning.

To conclude, learning based on the case method for general practitioners resulted in a beneficial change in clinical practice. Conventional introduction of practice guidelines had no effect. We would strongly question the impact on patient outcome of practice guidelines in themselves and advocate complementary methods aimed at changing the attitude and behaviour of physicians.

	Acknowledgments

We thank research nurse Katarina Patzelt Brandt for skilful management of the interviews, blood sampling, and careful handling of the case report forms.

Contributors: PH and AK shared the conception and analysis of the study and the drafting and revising of the article. PH was responsible for the main design of the study and AK for the design of the educational intervention. PH and AK are guarantors for this article.

	Footnotes

Funding: Grants from Stockholm County Council and the Karolinska Institute.

Competing interests: None declared.

Two additional tables, two additional figures, randomisation details, and an example case are available on bmj.com

	References

Top Abstract Introduction Methods Results Discussion References

1.	Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S). Lancet 1994; 344: 1383-1389[CrossRef][Web of Science][Medline].
2.	EUROASPIRE I and II Group. Clinical reality of coronary prevention guidelines: a comparison of EUROASPIRE I and II in nine countries. Lancet 2001; 357: 995-1001[CrossRef][Web of Science][Medline].
3.	Grimshaw JM, Russell IT. Effect of clinical guidelines on medical practice: a systematic review of rigorous evaluations. Lancet 1993; 342: 1317-1322[CrossRef][Web of Science][Medline].
4.	Lomas J, Anderson GM, Domnick-Pierre K, Vayda E, Enkin MW, Hannah WJ. Do practice guidelines guide practice? The effect of a consensus statement on the practice of physicians. N Engl J Med 1989; 321: 1306-1311[Abstract].
5.	Dowie J. The research-practice gap and the role of decision analysis in closing it. Health Care Anal 1996; 4: 5-18[Web of Science][Medline].
6.	Tversky A, Kahneman D. The framing of decisions and the psychology of choice. Science 1981; 211: 453-458[Abstract/Free Full Text].
7.	Feinstein AR. "Clinical judgment" revisited: the distraction of quantitative models. Ann Intern Med 1994; 120: 799-805[Abstract/Free Full Text].
8.	Shaughnessy AF, Slawson DC. Are we providing doctors with the training and tools for lifelong learning? BMJ 1999; 319: 1280[Free Full Text].
9.	Mauffette-Leenders LA, Erskine JA, Leenders MR, Richard Ivey School of Business. Learning with cases. London, ON: Richard Ivey School of Business, University of Western Ontario, 1997.
10.	Leenders MR, Mauffette-Leenders LA, Erskine JA. Writing cases. 4th ed. London, ON: Research and Publications Division, School of Business Administration, University of Western Ontario, 2001.
11.	Roethlisberger FJ, Dickson WJ, Wright HA, Western Electric Company. Management and the worker: an account of a research program conducted by the Western Electric Company, Hawthorne works, Chicago. Cambridge, MA: Harvard University Press, 1939.
12.	Antonovsky A. Health, stress, and coping. San Francisco, CA: Jossey-Bass, 1979.
13.	Eagle KA, Lee TH, Brennan TA, Krumholz HM, Weingarten S. 28th Bethesda Conference. Task Force 2: guideline implementation. J Am Coll Cardiol 1997; 29: 1141-1148[CrossRef][Web of Science][Medline].
14.	Davis DA, Taylor-Vaisey A. Translating guidelines into practice: a systematic review of theoretic concepts, practical experience and research evidence in the adoption of clinical practice guidelines. CMAJ 1997; 157: 408-416[Abstract].
15.	Cantillon P, Jones R. Does continuing medical education in general practice make a difference? BMJ 1999; 318: 1276-1279[Free Full Text].
16.	Watkins C, Harvey I, Langley C, Gray S, Faulkner A. General practitioners' use of guidelines in the consultation and their attitudes to them. Br J Gen Pract 1999; 49: 11-15[Web of Science][Medline].
17.	Fairhurst K, Huby G. From trial data to practical knowledge: qualitative study of how general practitioners have accessed and used evidence about statin drugs in their management of hypercholesterolaemia. BMJ 1998; 317: 1130-1134[Abstract/Free Full Text].
18.	Owen PA, Allery LA, Harding KG, Hayes TM. General practitioners' continuing medical education within and outside their practice. BMJ 1989; 299: 238-240.
19.	Allery LA, Owen PA, Robling MR. Why general practitioners and consultants change their clinical practice: critical incident study. BMJ 1997; 314: 870-874[Abstract/Free Full Text].
20.	Marshall MN. Qualitative study of educational interaction between general practitioners and specialists. BMJ 1998; 316: 442-445[Abstract/Free Full Text].
21.	Greco PJ, Eisenberg JM. Changing physicians' practices. N Engl J Med 1993; 329: 1271-1273[Free Full Text].
22.	Lomas J, Enkin M, Anderson GM, Hannah WJ, Vayda E, Singer J. Opinion leaders vs audit and feedback to implement practice guidelines: delivery after previous cesarean section. JAMA 1991; 265: 2202-2207[Abstract/Free Full Text].
23.	Davis DA, Thomson MA, Oxman AD, Haynes RB. Evidence for the effectiveness of CME: a review of 50 randomized controlled trials. JAMA 1992; 268: 1111-1117[Abstract/Free Full Text].
24.	O'Brien T, Freemantle N, Oxman AD, Wolf F, Davis DA, Herrin J. Continuing education meetings and workshops: effects on professional practice and health care outcomes. Cochrane Database Syst Rev 2001(2):CD003030.
25.	Smits PB, Verbeek JH, de Buisonje CD. Problem based learning in continuing medical education: review of controlled evaluation studies. BMJ 2002; 324: 153-156[Free Full Text].

(Accepted 15 August 2002)