Patient values and preferences for decision making in antithrombotic therapy: A systematic review

Poster
2011 Madrid
MacLean S1, Mulla S1, Jankowski M2, Akl E3, Vandvik P4, Ebrahim S5, McLeod S6, Bhatnagar N7, Guyatt G1
1Department of Clinical Epidemiology and Biostatistics, McMaster University, Canada
2Department of Internal Medicine, Faculty of Medicine, Jagiellonian University Medical College, Krakow, Poland
3Department of Clinical Epidemiology and Biostatistics, McMaster University, Canada; Department of Medicine, State University of New York at Buffalo, NY, US
4Norwegian Knowledge Centre for the Health Services, and Department of Medicine Gjøvik, Innlandet Hospital Trust, Norway
5Department of Biostatistics and Clinical Epidemiology, McMaster University, Canada
6The Division of Emergency Medicine, Department of Medicine, Schulich School of Medicine & Dentistry, The University of Western Ontario
7Health Sciences Library, McMaster University

Background:

Development of clinical practice guidelines involves making trade-offs between desirable and undesirable consequences of alternative management strategies. Although the relative value of health states to patients should provide the basis for these trade-offs, few guidelines have systematically summarized the relevant evidence.

Objectives:

In preparation for the 9th iteration of the American College of Chest Physicians anti-thrombotic guidelines, we conducted a systematic review relating to values and preferences of patients considering anti-thrombotic therapy.

Methods:

We included studies examining patient preferences for alternative approaches to anti-thrombotic prophylaxis and studies that, in the context of anti-thrombotic prophylaxis or treatment, examined how patients value alternative health states and experiences with treatment. We conducted a systematic search and compiled structured summaries of the results. Steps in the process that involved judgment were conducted in duplicate.

Results:

We identified 48 eligible studies. Sixteen dealt with atrial fibrillation, 5 with venous thromboembolism, 4 with stroke or myocardial infarction prophylaxis, 6 with thrombolysis in acute stroke or myocardial infarction, and 17 with burden of anti-thrombotic treatment. Findings included: 1) Values and preferences for treatments and for health states consistently varied appreciably between individuals. 2) Factors that influence apparent preferences for health states include previous exposure to treatment, previous exposure to health states, and the occurrence of a health state as an adverse effect of treatment. 3) Varying methods of preference elicitation lead to different choices. 4) A reasonable trade-off to assume between stroke and bleeds would be a ratio of disutility of stroke to bleeds ranging from 2:1 to 3:1 (although there are troubling inconsistencies across studies). 5) For most patients, warfarin therapy does not have important negative impacts on quality of life, although there exists a minority for whom it does.

Conclusions:

Systematic reviews such as ours should become a standard for clinical practice guidelines.