Resource use and outcomes associated with initiation of injectable therapies for patients with type 2 diabetes mellitus

INTRODUCTION: Management of type 2 diabetes mellitus (T2DM) often requires intervention with oral and injectable therapies. Across National Health Service (NHS) England, injectable therapies may be initiated in secondary, intermediate or primary care. We wished to understand resource utilization, pathways of care, clinical outcomes, and experience of patients with T2DM initiated on injectable therapies. METHOD: We conducted three service evaluations of initiation of injectable therapies (glucagon-like peptide-1 receptor agonists (GLP-1 RAs) or basal insulin) for T2DM in primary, secondary and intermediate care. Evaluations included retrospective review of medical records and service administration; prospective evaluation of NHS staff time on each episode of patient contact during a 3-month initiation period; patient-experience survey for those attending for initiation. Data from each evaluation were analysed separately and results stratified by therapy type. RESULTS: A total of 133 patients were included across all settings; 54 were basal-insulin initiations. After initiation, the mean HbA(1c) level fell for both types of therapies, and weight increased for patients on basal insulin yet fell for patients on GLP-1 RA. The mean cost of staff time per patient per initiation was: £43.81 for GLP-1 RA in primary care; £243.49 for GLP-1 RA and £473.63 for basal insulin in intermediate care; £518.99 for GLP-1 RA and £571.11 for basal insulin in secondary care. Patient-reported questionnaires were completed by 20 patients, suggesting that patients found it easy to speak to the diabetes team, had opportunities to discuss concerns, and felt that these concerns were addressed adequately. CONCLUSION: All three services achieved a reduction in HbA(1c) level after initiation. Patterns of weight gain with basal insulin and weight loss with GLP-1 RA were as expected. Primary care was less resource-intensive and costly, and was driven by lower staff costs and fewer clinic visits.