Health care resource utilization and expenditures associated with the use of insulin glargine.

Background: Newer insulins, such as long-acting analogues, offer promise of better glycemic control, reduced risk for diabetes complications, and moderation of health care use and costs.

Objective: We studied initiation of insulin glargine to evaluate its association with subsequent health service utilization and estimated expenditures.

Methods: Patients of the Veterans Health Administration, US Department of Veterans Affairs (VA) who initiated insulin glargine (n=5064) in 2001-2002 were compared with patients receiving other insulin (n=69,944), matched on prescription month (index date). Inpatient and outpatient VA care in the 12 months after a patient's index date was evaluated using Tobit regression, controlling for prior utilization, demographic characteristics, comorbidities, glycosylated hemoglobin (HbA(1c)) levels, and diabetes severity. National average utilization costs and medication acquisition costs were used to estimate the value of VA expenditures.

Results: Compared with other insulin users, insulin glargine initiators had higher HbA(1c) values (8.72% vs 8.16%) prior to the index date, but greater subsequent HbA(1c) reduction (-0.50% vs -0.22%). After adjustment for age, prior utilization, HbA(1c) levels, and other factors, insulin glargine initiation was associated with 2.4 (95% CI, 1.1-3.7) fewer inpatient days for patients with any hospital admission (US $820 lower costs per initiator), 1.6 (1.2-1.9) more outpatient encounters ($279 higher costs per initiator), and $374 ($362-$387) higher costs for diabetes medications. The net difference was an average lower VA cost of $166 (-$290 to $622) per patient.

Conclusions: Insulin glargine use was associated with decreased inpatient days but increased outpatient care, and the value of the net change in utilization to VA offset the additional medication expenditures. Initiation of insulin glargine improves glycemic control and may reduce time in hospital without additional use of health resources.