Greater persistence and adherence to basal insulin therapy is associated with lower healthcare utilization and medical costs in patients with type 2 diabetes: a retrospective database analysis

Introduction We aimed to assess persistence and adherence to basal insulin therapy, their association with all-cause healthcare resource utilization (HCRU) and direct medical costs, and predictors of persistence and adherence in adults with type 2 diabetes.Research design and methods A retrospective cohort study was conducted with US adults with type 2 diabetes initiating basal insulin therapy between January 1, 2016, and December 31, 2018, using IQVIA PharMetrics Plus claims data. Persistence and adherence were assessed during 1 year post-initiation per previous definitions. Demographic/clinical characteristics were assessed during the 1 year pre-initiation. Inverse probability of treatment weighting (IPTW) was used to adjust for confounding variables. Post-IPTW, all-cause HCRU and direct medical costs were assessed during the first-year and second-year post-initiation by persistence and adherence status. Multivariable logistic regression was used to identify predictors of persistence and adherence.Results The final sample comprised 64,953 patients; 56.8% demonstrated persistence and 41.9% demonstrated adherence. Patients demonstrating persistence and adherence were significantly less likely to have a hospitalization than patients demonstrating non-persistence or non-adherence, respectively. In the second-year post-initiation, total mean all-cause direct medical costs per patient were lower for patients demonstrating persistence and significantly lower for patients demonstrating adherence. Prior use of both oral and injectable antidiabetic medication predicted persistence and adherence compared with patients with only prior oral antidiabetic medication use (persistence OR, 1.50 (95% CI, 1.44 to 1.57); adherence OR, 1.48 (95% CI, 1.42 to 1.55)).Conclusions Persistence and adherence to basal insulin was associated with fewer hospitalizations and lower direct medical costs.