Open Access to Innovative Drugs: Treatment Substitutions or Treatment Expansion?

Granting open access to new antipsychotic medications by the California Medicaid Program fostered the desired substitution of second-generation medications for conventional antipsychotics. However, open access also generated an immediate but temporary influx of previously treated patients, many with a recent institutionalization, who restarted drug therapy using the new antipsychotics. Persistence with initial therapy declined, but cost outcomes improved due primarily to reduced nursing home use. Racial disparities were also reversed. Program administrators must use caution when evaluating the impact of unrestricted access on drug therapy outcomes and treatment costs given the changes in the characteristics of patients seeking treatment.