Objective: Budget impact models are useful tools for managed care organizations to make drug formulary decisions. The objective of this study was to estimate the incremental budgetary change in per-member-per-month (PMPM) medical and pharmacy costs for atopic dermatitis (AD) or eczema after the introduction of pimecrolimus cream 1%, a topical calcineurin inhibitor.
Methods: Estimates of the percentage of patients seeking care, treatment patterns, and quantities of medications dispensed for AD were measured using 2001 and 2002 medical and pharmacy records in a proprietary database for health plans distributed throughout the United States. Approximately 2.5 million health plan members had continuous health insurance coverage during the study period. Costs for medications were assigned using the 2003 wholesale acquisition cost, and costs for physician visits were based on average 2003 Medicare reimbursement rates. Efficacy data from clinical trials were used to model the impact of pimecrolimus on subsequent physician visits. Sensitivity analyses were performed to evaluate the impact of varying the percentage of patients seeking care, practice patterns, medication quantities, percentage of pimecrolimus users, and levels of patient cost sharing.
Results: The estimated percentage of health plan members seeking care for AD in 2001 was 3.2%. The estimated total cost PMPM for AD treatment prior to introduction of pimecrolimus was 0.362 dollars for all covered lives, assuming no patient cost sharing. In the year after its introduction, 5.2% of the AD population filled a prescription for pimecrolimus. The incremental increase in pharmacy benefit cost was 0.008 dollars PMPM in 2003 dollars, but the total incremental medical and pharmacy cost was 0.002 dollars PMPM after accounting for the projected reduction in physician visit costs, representing a 0.7% increase in all AD-related costs. Based on sensitivity analyses, the incremental total cost PMPM after the introduction of pimecrolimus ranged from -0.004 dollars to 0.026 dollars.
Conclusion: Using claims data for the medical treatment of AD in 2001-2002 and the utilization of pimecrolimus, the addition of pimecrolimus as a treatment option for AD had a minimal impact on PMPM costs for AD-related care in 2003 dollars. As with all pharmacoeconomic models, health plans should perform their own budget forecasting using assumptions derived from their own pharmacy and medical claims data.