Patterns of glycaemic control in patients with type 2 diabetes mellitus initiating second‐line therapy after metformin monotherapy: Retrospective data for 10 256 individuals from the United Kingdom and Germany

AIM: To investigate determinants of change in glycated haemoglobin (HbA1c) in patients with type 2 diabetes mellitus (T2DM) at 6 months after initiating uninterrupted second‐line glucose‐lowering therapies. MATERIALS AND METHODS: This cohort study utilized retrospective data from 10 256 patients with T2DM who initiated second‐line glucose‐lowering therapy (switch from or add‐on to metformin) between 2011 and 2014 in Germany and the UK. Effects of pre‐specified patient characteristics on 6‐month HbA1c changes were assessed using analysis of covariance. RESULTS: Patients had a mean (standard error [SE]) baseline HbA1c of 8.68% (0.02); 28.5% of patients discontinued metformin and switched to an alternative therapy and the remainder initiated add‐on therapy. Mean (SE) unadjusted 6‐month HbA1c change was −1.27% (0.02). When adjusted for baseline HbA1c, 6‐month changes depended markedly on the magnitude of the baseline HbA1c (HbA1c <9%, −0.45% per unit increase in HbA1c; HbA1c ≥9%, −0.87% per unit increase in HbA1c). Adjusted mean 6‐month HbA1c reductions showed slight treatment differences (range, 0.92–1.09%; P < .001). Greater reductions in HbA1c were associated with second‐line treatment initiation within 6 months of T2DM diagnosis (1.36% vs 1.03% [P < .001]) and advanced age (≥70 years, 1.13%; <70 years, 1.02% [P < .001]). CONCLUSIONS: Many patients with T2DM have very high HbA1c levels when initiating second‐line therapy, indicating the need for earlier treatment intensification. Patient‐specific factors merit consideration when making treatment decisions.