Medical costs associated with type 2 diabetes complications and comorbidities.

Objectives: To estimate the direct medical costs associated with type 2 diabetes, its complications, and its comorbidities among U.S. managed care patients.

Study Design: Data were from patient surveys, chart reviews, and health insurance claims for 7109 people with type 2 diabetes from 8 health plans participating in the Translating Research Into Action for Diabetes (TRIAD) study between 1999 and 2002.

Methods: A generalized linear regression model was developed to estimate the association of patients' demographic characteristics, tobacco use status, treatments, related complications, and comorbidities with medical costs.

Results: The mean annualized direct medical cost was $2465 for a white man with type 2 diabetes who had been diagnosed fewer than 15 years earlier, was treated with oral medication or diet alone, and had no complications or comorbidities. We found annualized medical costs to be 10% to 50% higher for women and for patients whose diabetes had been diagnosed 15 or more years earlier, who used tobacco, who were being treated with insulin, or who had several other complications. Coronary heart disease, congestive heart failure, hemiplegia, and amputation were each associated with 70% to 150% higher costs. Costs were approximately 300% higher for end-stage renal disease treated with dialysis and approximately 500% higher for end-stage renal disease with kidney transplantation.

Conclusions: Most medical costs incurred by patients with type 2 diabetes are related to complications and comorbidities. Our cost estimates can help when determining the most cost-effective interventions to prevent complications and comorbidities.