Understanding patient cost-sharing thresholds for diabetes treatment attributes via a discrete choice experiment

BACKGROUND: The process used to prefer certain products across drug classes for diabetes is generally focused on comparative effectiveness and cost. However, payers rarely tie patient preference for treatment attributes to formulary management resulting in a misalignment of value defined by providers, payers, and patients. OBJECTIVES: To explore patients’ willingness to pay (WTP) for the predetermined high-value and low-value type 2 diabetes mellitus (T2DM) treatments within a health plan. METHODS: A cross-sectional discrete choice experiment (DCE) survey was used to determine patient preference for the benefit, risk, and cost attributes of T2DM treatments. A comprehensive literature review of patient preference studies in diabetes and a review of guidelines and medical literature identified study attributes. Patients and diabetes experts were interviewed and instructed to identify, prioritize, and comment on which attributes of diabetes treatments were most important to T2DM patients. The patients enrolled in a health plan were asked to respond to the survey. A multinomial logit model was developed to determine the relative importance and the patient’s WTP of each attribute. The patients’ relative values based on WTPs for T2DM treatments were calculated and compared with the treatments by a health plan. RESULTS: A total of 7 attributes were selected to develop a web-based DCE questionnaire survey. The responses from a total of 58 patients were analyzed. Almost half (48.3%) of the respondents took oral medications and injections for T2DM. The most prevalent side effects due to diabetes medications were gastrointestinal (43.1%), followed by weight gain (39.7%) and nausea (32.8%). Patients were willing to pay more for treatments with proven cardiovascular benefit and for the risk reduction of hospitalization from heart failure. On the other hand, they would pay less for treatments with higher gastrointestinal side effects. Patients were willing to pay the most for sodium-glucose cotransporter 2 inhibitor and glucagon-like peptide 1 receptor agonist agents and the least for dipeptidyl peptidase-4 inhibitors and thiazolidinediones. CONCLUSIONS: This study provides information to better align patient, provider, and payer preferences in both benefit design and value-based formulary strategy for diabetes treatments. A preferred placement of treatments with cardiovascular benefits and lower adverse gastrointestinal side effects may lead to increased adherence to medications and improved clinical outcomes at a lower overall cost to both patients and their health plan.