Insulin Therapy in Patients with Type 2 Diabetes Mellitus

Objective: To support policy-making for patients with diabetes mellitus we compared the costs and effectiveness of initiation of insulin therapy in patients with type 2 diabetes mellitus in 2 settings in The Netherlands. Design: Retrospective cohort study. Setting: A shared-care setting and an outpatient care setting of a university hospital. Both settings are located in Amsterdam, The Netherlands. Patients: All patients with type 2 diabetes mellitus above 40 years of age who were transferred to insulin therapy in 1993 in both settings. Intervention: Initiation and monitoring of insulin therapy in patients with type 2 diabetes mellitus. Study perspective: Healthcare sector. Main outcome measures: Baseline and 12 months glycosylated hemoglobin (HbA_1c) values and fasting blood glucose levels, and direct healthcare costs of insulin therapy. Costs were expressed in 1996 Dutch guilders (NLG) [NLG1 = 0.5 US dollars ($US)]. Results: In the shared-care setting (n = 57) the per patient healthcare costs during 1 year of follow-up averaged NLG2467. In the secondary care setting (n = 45) healthcare costs averaged NLG2740. A sensitivity analysis demonstrated that healthcare costs per patient were in the same range in both settings, ranging from NLG2000 to about NLG3400 ($US1000 to $US1700). Mean HbA_1c values fell from 9.1 to 7.9% (shared-care setting; p < 0.05) and from 10.2 to 8.2% (secondary care setting; p < 0.05). The percentage of patients with poor glycemic control (HbA_1c >8.5%) decreased from 56 to 30% (shared-care setting) and from 76 to 36% (secondary care setting). The percentage of patients with good glycemic control (HbA_1c <7%) increased from 4 to 23% (shared-care setting) and from 2 to 18% (secondary care setting). Conclusions: The study shows that in the first year of insulin therapy in patients with type 2 diabetes mellitus, acceptable glycemic control (HbA_1c >8.5%) can be attained in the majority of patients in both a shared-care and a secondary care setting, at comparable low average costs per patient.