Acute Diabetes Complications After Transition to a Value-Based Medication Benefit.

Importance: The association of value-based medication benefits with diabetes health outcomes is uncertain. Objective: To assess the association of a preventive drug list (PDL) value-based medication benefit with acute, preventable diabetes complications. Design, Setting, and Participants: This cohort study used a controlled interrupted time series design and analyzed data from a large, national, commercial health plan from January 1, 2004, through June 30, 2017, for patients with diabetes aged 12 to 64 years enrolled through employers that adopted PDLs (intervention group) and matched and weighted members with diabetes whose employers did not adopt PDLs (control group). All participants were continuously enrolled and analyzed for 1 year before and after the index date. Subgroup analysis assessed patients with diabetes living in lower-income and higher-income neighborhoods. Data analysis was performed between August 19, 2020, and December 1, 2023. Exposure: At the index date, intervention group members experienced employer-mandated enrollment in a PDL benefit that was added to their follow-up year health plan. This benefit reduced out-of-pocket costs for common cardiometabolic drugs, including noninsulin antidiabetic agents and insulin. Matched control group members continued to have cardiometabolic medications subject to deductibles or co-payments at follow-up. Main Outcomes and Measures: The primary outcome was acute, preventable diabetes complications (eg, bacterial infections, neurovascular events, acute coronary disease, and diabetic ketoacidosis) measured as complication days per 1000 members per year. Intermediate measures included the proportion of days covered by and higher use (mean of 1 or more 30-day fills per month) of antidiabetic agents. Results: The study 10 588 patients in the intervention group (55.2% male; mean [SD] age, 51.1 [10.1] years) and 690 075 patients in the control group (55.2% male; mean [SD] age, 51.1 [10.1] years) after matching and weighting. From baseline to follow-up, the proportion of days covered by noninsulin antidiabetic agents increased by 4.7% (95% CI, 3.2%-6.2%) in the PDL group and by 7.3% (95% CI, 5.1%-9.5%) among PDL members from lower-income areas compared with controls. Higher use of noninsulin antidiabetic agents increased by 11.3% (95% CI, 8.2%-14.5%) in the PDL group and by 15.2% (95% CI, 10.6%-19.8%) among members of the PDL group from lower-income areas compared with controls. The PDL group experienced an 8.4% relative reduction in complication days (95% CI, -13.9% to -2.8%; absolute reduction, -20.2 [95% CI, -34.3 to -6.2] per 1000 members per year) compared with controls from baseline to follow-up, while PDL members residing in lower-income areas had a 10.2% relative reduction (95% CI, -17.4% to -3.0%; absolute, -26.1 [95% CI, -45.8 to -6.5] per 1000 members per year). Conclusions and Relevance: In this cohort study, acute, preventable diabetes complication days decreased by 8.4% in the overall PDL group and by 10.2% among PDL members from lower-income areas compared with the control group. The results may support a strategy of incentivizing adoption of targeted cost-sharing reductions among commercially insured patients with diabetes and lower income to enhance health outcomes.