An analysis of the effect of managed care implementation of prescription drug utilization by Texas Medicaid clients

This study measured prescription drug utilization and payment changes when Texas Medicaid clients in the Bexar County Service Area moved from a fee-forservice (FFS) to either a health maintenance organization (HMO) or primary care case management (PCCM) health care delivery model. Drug utilization and payment patterns were compared for a six-month period before and a six-month period after the managed care pilot program implementation. Medicaid clients in FFS, HMO, and PCCM programs in three other geographical areas across the state served as comparison groups with the experimental groups in Bexar County. Significant differences across plan designs were found in the mean changes of the following variables between study periods for child and adult clients: 1) prescription drug use rates; 2) the proportion of generic drug use; 3) prescription drug vii payments per claim; and 4) prescription drug payments per client. Furthermore, these changes were found to be significantly different across plan designs for child and adult antibiotic claims, and for child antidepressant claims. Significant differences were found for the following variables for child and adult antihistamine claims, and for child NSAID claims: 1) the proportion of generic drug use; 2) prescription drug payments per claim; and 3) prescription drug payments per client. And for adult antidepressant and NSAID claims, significant differences were found in the following variables: 1) prescription drug use rates; 2) the proportion of generic drug use; and 3) prescription drug payments per client. This study provided evidence of a managed care spillover effect on the prescription drug utilization of Medicaid managed care patients with a carved-out drug benefit. The results of this study should be helpful to Medicaid administrators who make decisions about managed care programs and carved-out drug benefits