Factors associated with choice of intensification treatment for type 2 diabetes after metformin monotherapy: a cohort study in UK primary care

Samantha Wilkinson,1 Ian J Douglas,1 Elizabeth Williamson,1 Heide A Stirnadel-Farrant,2 Damian Fogarty,3 Ana Pokrajac,4 Liam Smeeth,1 Laurie A Tomlinson1 1Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK; 2GlaxoSmithKline, Stevenage, UK; 3Belfast Health and Social Care Trust, Belfast, UK; 4West Herts Hospitals NHS Trust, Watford, UK Purpose: To understand the patient characteristics associated with treatment choice at the first treatment intensification for type 2 diabetes.Patients and methods: This is a noninterventional study, using UK electronic primary care records from the Clinical Practice Research Datalink. We included adults treated with metformin monotherapy between January 2000 and July 2017. The outcome of interest was the drug prescribed at first intensification between 2014 and 2017. We used multinomial logistic regression to calculate the ORs for associations between the drugs and patient characteristics.Results: In total, 14,146 people started treatment with an intensification drug. Younger people were substantially more likely to be prescribed sodium-glucose co-transporter-2 inhibitors (SGLT2is), than sulfonylureas (SUs): OR for SGLT2i prescription for those aged <30 years was 2.47 (95% CI 1.39–4.39) compared with those aged 60–70 years. Both overweight and obesity were associated with greater odds of being prescribed dipeptidyl peptidase-4 inhibitor (DPP4i) or SGLT2i. People of non-white ethnicity were less likely to be prescribed SGLT2i or DPP4i: compared with white patients, the OR of being prescribed SGLT2i among South Asians is 0.60 (95% CI 0.42–0.85), and for black people, the OR is 0.54 (95% CI 0.30–0.97). Lower socioeconomic status was also independently associated with reduced odds of being prescribed SGLT2is.Conclusion: Both clinical and demographic factors are associated with prescribing at the first stage of treatment intensification, with older and non-white people less likely to receive new antidiabetic treatments. Our results suggest that the selection of treatment options used at the first stage of treatment intensification for type 2 diabetes is not driven by clinical need alone. Keywords: drug prescriptions, diabetes mellitus, type 2, hypoglycemic agents, primary health care, practice patterns, physician