The valium project: diagnostic restrictions as a utilization control in a Medicaid drug program.

This study examines the effectiveness of diagnosis restrictions as a drug utilization control in California's Medi-Cal (Medicaid) program. The numbers of Valium prescriptions dispensed, the numbers of Medi-Cal beneficiaries using Valium and the expenditures represented by those prescriptions were measured during application of a diagnosis restriction for a 33-month base period, followed by removal of the diagnosis restriction for a 14-month period.