Analysis of Cost and Utilization of Health Care Services Before and After Initiation of Insulin Therapy in Patients With Type 2 Diabetes Mellitus

OBJECTIVES: This study analyzed the cost and utilization of health care services before and after the initiation of insulin in treating patients with type 2 diabetes mellitus (DM) to determine if disease-related and total health care costs decreased after patients were started on insulin therapy. METHODS: 1,177 patients with type 2 DM between the ages of 18 and 65 years and continuously enrolled in a managed care organization for 9 months before and after their insulin start date were included in the study. Medical, facility, and pharmaceutical services in the pre insulin and post insulin time period were examined along with a sub analysis of all types of medical service categories. Trending analysis was performed by dividing the post insulin time period into mutually exclusive 2-month periods. The costs of total and disease-related services were studied over these intervals. RESULTS: Analysis of the total 9-month pre insulin and 9-month post insulin periods determined that average total and disease-related costs increased after insulin was started, with a mean difference of $2,220 (P less than 0.001) for average total costs and $430 (P less than 0.001) for disease-related costs. Trending analysis, though, demonstrated that much of the cost increase after the start of insulin occurred in the initial 2-month post insulin period, after which both total costs and disease-related costs decreased by 57% (P less than 0.001) and 49% (P less than 0.001), respectively, throughout the remainder of the post insulin time period. Facility costs decreased at all post insulin measurement intervals, while pharmacy costs were the only treatment component to remain above the pre insulin period. Pharmacy services accounted for a greater proportion of the costs in treating patients with type 2 DM in the post insulin time period, increasing from 19.8% of costs at baseline to 42.8% at post insulin months 6 to 8. CONCLUSIONS: The initiation of insulin therapy in the management of type 2 DM involves an approximate 10% increase in total health care expenditures initially, although this is offset by the consistent and substantial 40% decrease in subsequent total health care expenditures 9 months following insulin initiation.