Abstract
Background
Adherence and persistence to antidiabetes medications are important to control blood glucose levels among individuals with type 2 diabetes mellitus (T2D).
Objectives
The objective of this study was to compare adherence and persistence over a 12-month period between patients initiating saxagliptin and patients initiating linagliptin, two dipeptidyl peptidase-4 inhibitors.
Methods
This retrospective cohort study was conducted in MarketScan® Commercial and Medicare Supplemental claims databases. Patients with T2D initiating saxagliptin or linagliptin between January 1, 2009, and June 30, 2013, were selected. Patients were required to be at least 18 years old and have 12 months of continuous enrollment prior to and following initiation. Adherence and persistence to initiated medication were measured over the 12 months after initiation using outpatient pharmacy claims. Patients were considered adherent if the proportion of days covered was ≥0.80. Patients were considered nonpersistent (or to have discontinued) if there was a gap of >60 days without initiated medication on hand. Multivariable logistic regression and multivariable Cox proportional hazard models were fit to compare adherence and persistence, respectively, between the two cohorts.
Results
There were 21,599 saxagliptin initiators (mean age 55 years; 53% male) and 5,786 linagliptin initiators (mean age 57 years; 54% male) included in the study sample. Over the 12-month follow-up, 46% of saxagliptin initiators and 42% of linagliptin initiators were considered adherent and 47% of saxagliptin initiators and 51% of linagliptin initiators discontinued their initiated medication. After controlling for patient characteristics, saxagliptin initiation was associated with significantly greater odds of being adherent (adjusted odds ratio =1.212, 95% CI 1.140–1.289) and significantly lower hazards of discontinuation (adjusted hazard ratio =0.887, 95% CI 0.850–0.926) compared with linagliptin initiation.
Conclusion
Compared with patients with T2D who initiated linagliptin, patients with T2D who initiated saxagliptin had significantly better adherence and persistence.
Acknowledgments
The analysis was funded by AstraZeneca. Portions of this analysis were presented at AMCP Nexus 2015, October 26–29, 2015, Orlando, FL, USA. The poster’s abstract was published in the Journal of Managed Care & Specialty Pharmacy, supplement volume 21, number 10-a and may be found here: http://www.amcp.org/WorkArea/DownloadAsset.aspx?id=20165.
Disclosure
JJS was an employee of AstraZeneca, which funded this analysis, at the time it was conducted. AMF, BMD, and DMS are employees of Truven Health Analytics, which received funding for this analysis. The authors report no other conflicts of interest in this work.