Evaluation of glycemic control and medication utilization patterns in patients with type 2 diabetes mellitus on sodium glucose cotransporter 2 inhibitors compared to dipeptidyl peptidase IV inhibitors
Objectives: To compare patient demographics, glycemic control and medication utilization patterns in type-2 diabetes patients initiating Sodium Glucose Cotransporter 2 Inhibitors (SGLT2-I) or Dipeptidyl Peptidase IV Inhibitors (DPP4-I). Methods: Retrospective analysis of medical and pharmacy claims from the Scott and White Health Plan. Patient > 18 and < 62 years old with a diagnosis of type 2 DM ([ICD-9-CM] of 250.X0 or 250.X2) with a six-month continuous enrollment criterion during the study period were included. Patients on either a SGLT2-I or DPP4-I and a glucagon like peptide-1 agents were excluded. Demographic, clinical, and economic characteristics were assessed at baseline. Adherence was measured using proportion of days covered greater than 80% and persistence was defined as number of days until treatment discontinuation with a gap in therapy of 45 days. Mann-Whitney U or chi-square tests were used to compare cohorts. Multivariable linear regression models assessed baseline factors associated with change in A1C. Results: Analysis included a total of 99 SGLT2-I and 201 DPP4-I patients. The average age (50.9 vs 52.2, p=0.1559), and Charlson comorbidity index (2.25 vs 2.11, p=0.1359) were comparable. The SGLT2-I cohort had a lower proportion of patients receiving sulfonylureas (45% vs. 65%, p=0.0011), a higher proportion receiving insulin (62% vs. 31%, p <0.001) and a higher baseline A1C (8.9 vs. 8.3, p=0.0324). The SGLT2-I cohort was found to be less persistent than the DPP4-I cohort with a mean time to treatment discontinuation of 181.5 days compared to 210.1 days (p = 0.0497). Though the change in A1C was not statistically significant, clinically the SGLT2-I had a larger decrease in A1C of -0.7 compared to -0.5 in the DPP4-I cohort. Conclusion: In our sample, there was no statistical difference in the improvement of glycemic control (A1C) between a SGLT2-I or a DPP4-I. Medication utilization patterns also did not differ between either cohorts, except that patients in the SGLT2-I cohort were found to be less persistent than the DPP4-I cohort. Limitations of the study include a small sample size and a limited study period of one year.