Relationship of Glycemic Control to Total Diabetes-Related Costs for Managed Care Health Plan Members With Type 2 Diabetes

OBJECTIVES: Glycosylated hemoglobin (A1c) is a well-established measure of glycemic control, and evidence suggests that maintaining an acceptable A1c level may be associated with lower treatment costs in adults with diabetes. Understanding the impact on total treatment costs of staying at the target A1c level is of great importance to managed care organizations. The goal of this study was to determine whether type 2 diabetes patients at or below the target A1c level of 7% had lower diabetes-related costs compared with patients above an A1c level of 7%. METHODS: This study was a retrospective database analysis using eligibility data, medical and pharmacy claims data, and laboratory data from a large U.S. health care organization. Patients were included in the study if they had 2 or more claims for type 2 diabetes (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes 250.x0 or 250.x2) and at least 1 A1c value (first such date defined as the index date) during the 12-month period from January 1, 2002, through December 31, 2002. Patients with 2 or more medical claims for type 1 diabetes (ICD-9-CM codes 250.x1 or 250.x3) were excluded from the study. Study patients were divided into 2 groups, those at the target A1c level (²7%) and those at the above-target A1c level (greater than 7%), and were followed for a period of 1 year after their index date. Demographic, clinical, and cost variables were extracted from the administrative database. Multiple linear regression analysis was used to compare treatment costs between patients at the target A1c level and patients above target level. RESULTS: A total of 3,121 patients (46.0%) were identified as being at the target A1c level, and 3,659 patients (54%) were identified as being above the target A1c level during the study period. After controlling for confounding factors, the predicted total diabetes-related cost for the above-target group during the 1-year follow-up period was $1,540 per patient, 32% higher than the total diabetes related cost ($1,171) for the at-target group (P less than 0.001). CONCLUSIONS: Results of this analysis suggest that managed care members with type 2 diabetes who stayed continuously at the target A1c level of 7% or less over a 1-year follow-up period incurred lower diabetes-related costs compared with managed care members with type 2 diabetes who were continuously over the target A1c level of 7%.