Antipsychotic prescribing practices in the Veterans Healthcare Administration--New York metropolitan region.

Most research literature concerning pharmacological treatments reports results from controlled clinical trials, which provide data critical to assess the efficacy of new treatments in research populations. Fewer studies examine how treatments are adopted in everyday practice settings, where comorbid disorders and environmental issues typically complicate patients' situations. In this study, we examine the evolution of antipsychotic prescribing practices in the New York region of the Veterans Healthcare Administration (VHA) from 1998 to 2000 using administrative data. Second generation antipsychotic medications are now prescribed more frequently than the older antipsychotic medications, with a concomitant increase in cost. Data show low rates of clozapine use, relatively high rates of polypharmacy, and intersite variation in prescribing practices. Additional research in everyday practice settings is needed to address clinical questions unlikely to be answered through traditional efficacy research and to examine reasons for intersite differences in prescribing patterns.