Longer medication persistence in type 2 diabetes (T2D) is associated with improved glycaemic control. It is not clear which oral therapies have the best persistence.

To compare medication persistence across different oral therapies in people with T2D.

We performed a retrospective cohort analysis using a primary care based population, the Royal College of General Practitioners Research and Surveillance Centre cohort. We identified new prescriptions for oral diabetes medication in people with type 2 diabetes between 1st January 2004 and 31st July 2015. We compared median persistence across each class (non-persistence defined as prescription gap of ≥ 90 days). We also compared non-persistence between classes, adjusting for confounders, using Cox regression. Confounders included: age, gender, ethnicity, socioeconomic status, alcohol use, smoking status, glycaemic control, diabetes duration, diabetes complications, comorbidities, and number of previous and concurrent diabetes medications.

We identified 60,327 adults with T2D. The majority 42,810 (70.9%) of people had one or more oral medications prescribed. In these patients we measured persistence with 55,728 oral medications. Metformin had the longest median persistence (3.04 years; 95% CI 2.94 to 3.12). The adjusted hazard ratios for non-persistence compared with metformin were: sulfonylureas HR 1.20 (1.16 to 1.24), DPP-4 inhibitors HR 1.43 (1.38 to 1.49), thiazolidinediones HR 1.71 (95% CI 1.64-1.77), SGLT2 inhibitors HR 1.04 (0.93 to 1.17), meglitinides HR 2.25 (1.97 to 2.58), and alpha-glucosidase inhibitors HR 2.45 (1.98 to 3.02). The analysis of SGLT2 inhibitors was limited by the short duration of follow-up for this new class. Other factors associated with reduced medication persistence are female gender, younger age, and non-white ethnicity.

Persistence is strongly influenced by medication class and should be considered when initiating treatments.