Evaluation of patients with type 2 diabetes mellitus receiving treatment during the pre-diabetes period: Is early treatment associated with improved outcomes?

Aim: This study evaluates the association of pretreatment with oral antidiabetics (OADs) on clinical outcomes and health resource utilization among commercially insured type II diabetes mellitus (T2DM) patients in the United States.

Methods: Using administrative data (Truven MarketScan® Research Databases), patients diagnosed with T2DM between 2007 and 2014 with ⩾6months continuous enrolment pre- and post-diagnosis were evaluated. Pretreatment was defined as OAD use at least 3months prior to T2DM diagnosis. Time-to-insulin initiation and healthcare costs were compared by OAD pretreatment status.

Results: Of the 866,605 patients studied, 241,856 (27.9%) were pretreated prior to T2DM diagnosis. Mean follow-up was 2.9years for pretreatment and 3.1years for those without pretreatment. Monthly diabetes-related pharmacy costs were significantly higher among pretreated patients ($66 versus $36, p<0.0001), as were overall monthly pharmacy costs ($255 versus $198, p<0.0001). Pretreated patients had lower mean monthly costs, both total ($625 versus $671, p<0.0001) and diabetes-related ($207 versus $214, p=0.0012). After multivariable adjustment, mean monthly diabetes-related total healthcare costs were higher among pretreated patients (+$60) but total all-cause monthly healthcare costs were significantly lower (-$354) (both p<0.05). Pretreatment was associated with a lower insulin initiation probability for 2years, after which probability was similar; the adjusted hazard ratio for pretreatment in a time-to-insulin model was 0.96 (95% CI, 0.94-0.97).

Conclusions: Pretreatment with OADs is associated with a modest delay in initiating insulin therapy and lower total healthcare costs. The clinical and pharmacoeconomic benefits of pretreatment should be elucidated in a prospective study.