Effects of patients' preferences on the treatment of atrial fibrillation: observational study of patient-based decision analysis

Abstract

ⅷ Objective To investigate the effect of patients' preferences in the treatment of atrial fibrillation by using individualized decision analysis in which probability and utility assessments are combined into a decision tree.ⅷ Design Observational study based on interviews with patients.ⅷ Setting 8 general practices in Avon, England.ⅷ Participants 260 randomly selected patients aged 70 to 85 years with atrial fibrillation.ⅷ Main outcome measures Patients' treatment preferences regarding anticoagulation treatment (warfarin sodium) after individualized decision analysis; comparison of these preferences with treatment guidelines on the basis of comorbidity and absolute risk and compared with current prescription.ⅷ Results Of 195 eligible patients, 97 participated in decision making using decision analysis.Among these 97, the decision analysis indicated that 59 (61%; 95% confidence interval, 50%-71%) would prefer anticoagulation treatment, considerably fewer than those who would be recommended treatment according to guidelines.There was marked disagreement between the decision analysis and guideline recommendations (Ն0.25).Of 38 patients whose decision analysis indicated a preference for anticoagulation, 17 (45%) were being prescribed warfarin; on the other hand, 28 (47%) of 59 patients were not being prescribed warfarin, although the results of their decision analysis suggested they wanted to be.ⅷ Conclusions In the context of shared decision making, individualized decision analysis is valuable in a sizable proportion of elderly patients with atrial fibrillation.Taking account of patients' preferences would lead to fewer prescriptions for warfarin than under published recommendations.Decision analysis as a shared decision-making tool should be evaluated in a randomized controlled trial.Atrial fibrillation is an independent risk factor for stroke.Randomized trials have established that anticoagulation with warfarin sodium is associated with a relative reduction in the risk of stroke of 68%. 1 Community-based studies that estimated the prevalence of atrial fibrillation, however, show underdiagnosis and undertreatment.2,3 Commentators from general practice attribute the poor incorporation of this treatment in clinical practice to a lack of representativeness of patients enrolled in clinical trials.In particular, patients managed in primary care may be more likely than patients in clinical trials to find "minor" side effects from anticoagulation problematic.4,5 Decision analysis is a form of shared decision making that explicitly combines the probabilities of events resulting from treatment decisions with quantitative estimates of patients' perceptions (utilities) regarding the consequences of treatment.6 The increasing computerization in general practices, along with the development of userfriendly software, means that utility assessment with decision analysis is a realistic aim for decision making with individual patients.7 Qualitative research has established that patients' health beliefs are important factors in determining whether they accept or decline anticoagulation treatment for atrial fibrillation.8 We examined the effects of patients' preferences, measured by utility assessment, on treatment choices and compared this method of decision making with evidence-based recommendations based on age and comorbidity or absolute risk of stroke.9-11 METHODS Selection of participantsWe invited 17 general practices to take part in the study, of which 13 accepted.Owing to time constraints, only the Summary points• Qualitative research has established patients' preferences as a major factor in determining choice of anticoagulation treatment in patients with atrial fibrillation• Decision analysis is a form of shared decision making that explicitly combines the probabilities of events resulting from treatment decisions with quantitative estimates of the patients' preferences• This study shows that eliciting patients' preferences and performing decision analysis has a major effect on a patient's preference for anticoagulation treatment• Evaluation of decision analysis as a shared decision-making tool and its effect on patients' knowledge, satisfaction, uptake, and adherence to anticoagulation treatment should be examined in a randomized controlled trial