OBJECTIVES: Therapeutic inertia is the failure of health-care providers to initiate or intensify therapy when therapeutic goals are not reached. Few studies have compared insulin initiation delay times with their expected negative effect on health outcomes. Our study quantifies the effects of delaying the start of insulin for patients with Type 2 Diabetes Mellitus (T2DM) on future A1c values, medical costs, and development of new T2D-related complications.

METHODS: Retrospective paid claims data from 2008 to 2019 was retrieved from the OPTUM database including data on prescriptions fill history, lab values, hospitalizations, and patient demographics. Based on the American Diabetes Association (ADA) guidelines, insulin is recommended for patients who have an A1C greater than 10%. Patients matching this criteria were selected and insulin delay time was defined as the time between the initiation of insulin and the patient’s first recorded A1C above 10%. Patients were then grouped by months of delay up to 1 year to compare outcomes. Differences in healthcare costs and the risk of developing vascular complications were compared across patients depending on their delay category.

RESULTS: An initial 1% sample of the OPTUM file revealed that most patients who exceed an A1c > 10 do not initiate insulin at any time in their post data. Additionally, patients treated with insulin within 3 months of A1c > 10 appeared to be 'sicker' with medical costs prior to their A1C >10 exceeding $12,000 while the other groups who delayed more than 3 months had prior medical costs around $5,000. Finally, the group that never initiated insulin had fewer events post regardless of the baseline from which this is measured. CONCLUSION: Patients are delaying starting insulin until they have an event. Our plans are to better document the risk of events and the costs associated with this behavior.