The Direct Medical Cost of Type 2 Diabetes

Brandle, Michael MD
Zhou, Honghong MS
Smith, Barbara R.K. MHSA
Marriott, Deanna MAS
Burke, Ray MA
Tabaei, Bahman P. MPH
Brown, Morton B. PHD
Herman, William H. MD, MPH

From the ¹Division of Endocrinology & Metabolism, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan; the ²Department of Biostatistics, University of Michigan, Ann Arbor, Michigan; the ³Department of Epidemiology, University of Michigan, Ann Arbor, Michigan; and the ⁴Michigan Diabetes Research and Training Center, University of Michigan, Ann Arbor, Michigan.

Address correspondence and reprint requests to William H. Herman, University of Michigan Health System, Division of Endocrinology and Metabolism, 1500 East Medical Center Dr., 3920 Taubman Center, Ann Arbor, MI 48109-0354. E-mail: [email protected].

Received for publication 19 March 2003 and accepted in revised form 8 May 2003.

Abbreviations: CPT, current procedural terminology; DRG, diagnosis-related group; ESRD, end-stage renal disease; HMO, health maintenance organization; IQR, interquartile range; MI, myocardial infarction.

A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

Diabetes Care 26(8):p 2300-2304, August 2003.

OBJECTIVE

To describe the direct medical costs associated with type 2 diabetes, as well as its treatments, complications, and comorbidities.

RESEARCH DESIGN AND METHODS

We studied a random sample of 1,364 subjects with type 2 diabetes who were members of a Michigan health maintenance organization. Demographic characteristics, duration of diabetes, diabetes treatments, glycemic control, complications, and comorbidities were assessed by surveys and medical chart reviews. Annual resource utilization and costs were assessed using health insurance claims. The log-transformed annual direct medical costs were fitted by multiple linear regression to indicator variables for demographics, treatments, glycemic control, complications, and comorbidities.

RESULTS

The median annual direct medical costs for subjects with diet-controlled type 2 diabetes, BMI 30 kg/m², and no microvascular, neuropathic, or cardiovascular complications were $1,700 for white men and $2,100 for white women. A 10-kg/m² increase in BMI, treatment with oral antidiabetic or antihypertensive agents, diabetic kidney disease, cerebrovascular disease, and peripheral vascular disease were each associated with 10-30% increases in cost. Insulin treatment, angina, and MI were each associated with 60-90% increases in cost. Dialysis was associated with an 11-fold increase in cost.

CONCLUSIONS

Insulin treatment and diabetes complications have a substantial impact on the direct medical costs of type 2 diabetes. The estimates presented in this model may be used to analyze the cost-effectiveness of interventions for type 2 diabetes.