Patterns of initial and first-intensifying antidiabetic drug utilization among patients with type 2 diabetes mellitus in Scotland, 2010-2020: A retrospective population-based cohort study.

AIM

To evaluate the utilization and prescribing patterns of antidiabetic drugs (ADDs) for patients with type 2 diabetes mellitus (T2DM) at treatment initiation and first intensification.

METHODS

A retrospective cohort study was performed using linked routinely collected data of patients with T2DM who received ADDs between January 2010 and December 2020 in Scotland. The prescribing patterns were quantified using frequency/percentages, absolute/relative change, and trend tests.

RESULTS

Overall, 145 909 new ADD users were identified, with approximately 91% (N = 132 382) of patients receiving a single ADD at first treatment initiation. Metformin was the most often prescribed monotherapy (N = 118 737, 89.69%). A total of 50 731 patients (39.40%) who were started on metformin (N = 46 730/118 737, 39.36%) or sulphonylurea (SU; N = 4001/10 029, 39.89%) monotherapy had their treatment intensified with one or more additional ADD. Most initial-metformin (45 963/46 730; 98.36%) and initial-SU users (3894/4001; 97.33%) who added further drugs were intensified with single ADDs. SUs (22 197/45 963; 48.29%) were the most common first-intensifying monotherapy after initial metformin use, but these were replaced by sodium-glucose cotransporter-2 (SGLT2) inhibitors in 2019 (SGLT2 inhibitors: 2039/6065, 33.62% vs. SUs: 1924/6065, 31.72%). Metformin was the most frequently added monotherapy to initial SU use (2924/3894, 75.09%). Although the majority of patients received a single ADD, the use of combination therapy significantly increased over time. Nevertheless, there was a significant increasing trend towards prescribing the newer ADD classes (SGLT2 inhibitors, dipeptidyl peptidase-4 inhibitors) as monotherapy or in combination compared with the older ones (SUs, insulin, thiazolidinediones) at both drug initiation and first intensification.

CONCLUSIONS

An overall increasing trend in prescribing the newer ADD classes compared to older ADDs was observed. However, metformin remained the most commonly prescribed first-line ADD, while SGLT2 inhibitors replaced SUs as the most common add-on therapy to initial metformin use in 2019.