Factors that affect adherence to bipolar disorder treatments: A stated-preference approach
BACKGROUND: Medication nonadherence is high among patients with bipolar disorder, and may lead to poor clinical outcomes, decreased quality of life, and increased resource utilization. OBJECTIVE: To investigate the factors associated with nonadherence and to assess the effect of patient-stated preferences on stated adherence to hypothetical medications. RESEARCH DESIGN: A choice-format stated-preference Web survey was administered. In each choice question, patients were asked to choose among 2 or 3 different hypothetical medications. Each choice question was followed by a question asking patients about their likely adherence to the selected medication alternative. SUBJECTS: Patients (N = 469) with self-reported bipolar disorder completed the survey which was programmed and administered to members of a chronic-illness Web panel. MEASURES:: Factors associated with stated adherence to current treatment were identified. The effects of socioeconomic characteristics and medication attributes on stated adherence to hypothetical medications were assessed. RESULTS: Patient socioeconomic characteristics affect patients' adherence. Being white and having more education has a significant positive effect on adherence. Self-reported current adherence is a strong factor in predicting adherence for better medications. Medication outcome attributes, especially severity of depressive episodes, strongly influence patients' stated adherence to treatment. Weight gain and cognitive effects of a medication most significantly affected patients' likely adherence to medications for bipolar disorder. CONCLUSIONS: Patients are the final health care decision makers; their satisfaction with a medication is likely to affect whether or not they adhere to the medication prescribed by their physician. In the case of bipolar disorder, this study suggests patients are likely to be more adherent to medications that reduce the severity of depressive episodes and do not cause weight gain or cognitive side effects. By understanding the factors that improve adherence, health care providers can optimize prescribing patterns, which may ultimately lead to more effective management and improvement in the patient's condition.