Objective: Describe the characteristics, costs, and adherence of patients receiving human regular U-500 insulin (U-500R) compared with those of patients receiving high-dose (≥150 units/day) U-100 insulin.
Methods: Data from Truven Health MarketScan Research Databases, July 1, 2008, through December 31, 2010, were used. The U-100 cohort received ≥150 units/day of U-100 insulin for ≥31 days during the first 60 days after the index date. The U-500R cohort received ≥2 prescriptions of U-500R after the index date. Analyses were performed on propensity-matched cohorts. The changes in annualized costs were compared between the 2 cohorts using paired t tests. Adherence was assessed by the proportion of days covered (PDC) and compared using a 2-sample t test. Glycemic efficacy data were not available in this database.
Results: There were 1,044 U-500R-treated patients (19.1% with type 1 diabetes [T1D]) and 11,520 U-100-treated patients (23.8% with T1D) identified, from which 1,039 matched pairs were obtained. The mean decrease of $1,290 in annual pharmacy costs for the U-500R cohort was significantly different from the mean increase of $2,586 for the U-100 cohort (P<.001; 95% confidence interval, -$4,345 to -$3,422). More U-500R patients experienced hypoglycemia (17.3% vs. 11.8%; P<.001), but the hypoglycemia rate per person and related costs were not significantly different between cohorts. Finally, the mean 12-month PDC was 65.0% for U-500R versus 47.6% for U-100 patients (P<.0001).
Conclusion: Compared with treatment with ≥150 units/day of U-100 insulin, treatment with U-500R was associated with decreases in pharmacy costs, a higher percentage of patients experiencing hypoglycemia, and greater treatment adherence.