Adherence and persistence rates for antidiabetic treatments in type 2 diabetes: a real-world study in an Italian region

Objective

Achieving glycaemic control is essential to avoid disease progression and diabetes-related complications. Non-adherence and discontinuity in diabetic therapy are major barriers to optimal glycaemic control. The aim of this study was to evaluate adherence, persistence and therapy switching over 1 year in real-life conditions in patients with type 2 diabetes within an Italian region.

Methods

A retrospective, observational, non-interventional study was conducted, analysing patients treated with Anatomical Therapeutic Chemical (ATC) Classification A10B drugs dispensed by pharmacies under the local health authority (ASL) of the Umbria region from 1 January 2022 to 31 December 2023. Adherence was measured using the Proportion of Days Covered (PDC), while persistence was calculated as the duration between the start and end of therapy.

Results

A total of 6928 patients with type 2 diabetes were analysed. After 1 year, the overall adherence rate was 0.78, with 58% (4017/6928) of patients having adherence greater than 0.80. The lowest adherence was observed in patients treated with metformin +dipeptidyl peptidase 4 (DPP4) inhibitors, with a mean adherence of 0.71 and 36% (142/395) of patients achieving adherence greater than 0.80. Conversely, the highest adherence was seen in patients on sodium-glucose co-transporter 2 (SGLT2) inhibitors, with a mean adherence of 0.91 and 97% (473/487) of patients achieving adherence greater than 0.80. Persistence data showed concerning results, with less than 10% of patients remaining on treatment for 1 year across all drug classes. Among patients initially treated with metformin (n=4427), there was a substantial loss to follow-up, with 3582 patients (81%) discontinuing treatment within the first year.

Conclusions

The 1 year data on adherence and persistence for antidiabetic drugs revealed concerning trends. These findings underscore the need for targeted interventions, involving clinicians and pharmacists, to improve adherence and persistence in patients with type 2 diabetes, ultimately ensuring better disease management and reducing long-term healthcare costs.