The incremental costs of recommended therapy versus real world therapy in type 2 diabetes patients

Abstract

Background: The goals of diabetes management have evolved over the past decade to become the attainment of near-normal glucose and cardiovascular risk factor levels. Improved metabolic control is achieved through optimized medication regimens, but costs specifically associated with such optimization have not been examined.

Objective: To estimate the incremental medication cost of providing optimal therapy to reach recommended goals versus actual therapy in patients with type 2 diabetes.

Methods: We randomly selected the charts of 601 type 2 diabetes patients receiving care from the outpatient clinics of Massachusetts General Hospital March 1, 1996-August 31, 1997 and abstracted clinical and medication data. We applied treatment algorithms based on 2004 clinical practice guidelines for hyperglycemia, hyperlipidemia, and hypertension to patients' current medication therapy to determine how current medication regimens could be improved to attain recommended treatment goals. Four clinicians and three pharmacists independently applied the algorithms and reached consensus on recommended therapies. Mean incremental medication costs, the cost differences between current and recommended therapies, per patient (expressed in 2004 dollars) were calculated with 95% bootstrap confidence intervals (CIs).

Results: Mean patient age was 65 years old, mean duration of diabetes was 7.7 years, 32% had ideal glucose control, 25% had ideal systolic blood pressure, and 24% had ideal low-density lipoprotein cholesterol. Care for these diabetes patients was similar to that observed in recent national studies. If treatment algorithm recommendations were applied, the average annual medication cost/patient would increase from 1525 to 2164 dollars. Annual incremental costs/patient increased by 168 dollars (95% CI 133-206 dollars) for antihyperglycemic medications, 75 dollars (57-93 dollars) for antihypertensive medications, 392 dollars (354-434 dollars) for antihyperlipidemic medications, and 3 dollars (3-4 dollars) for aspirin prophylaxis. Yearly incremental cost of recommended laboratory testing ranged from 77-189 dollars/patient.

Limitations: Although baseline data come from the clinics of a single academic institution, collected in 1997, the care of these diabetes patients was remarkably similar to care recently observed nationally. In addition, the data are dependent on the medical record and may not accurately reflect patients' actual experiences.

Conclusion: Average yearly incremental cost of optimizing drug regimens to achieve recommended treatment goals for type 2 diabetes was approximately 600 dollars/patient. These results provide valuable input for assessing the cost-effectiveness of improving comprehensive diabetes care.

Figure 1

Study patient selection procedure