Antipsychotic prescription use and costs for persons with schizophrenia inthe 1990s: current trends and five year time series forecasts

Real advances in schizophrenia pharmacotherapy have been made over this dec ade with the development of more efficacious treatment options with fewer s ide-effects. These advances have high per-unit direct costs that may have a profound effect on drug budgets of systems caring for persons with schizop hrenia. The objective of this study was to describe the changes in utilizat ion and cost for antipsychotic prescriptions by atypical, clozapine, decano ate products, and traditional neuroleptics in a large naturalistic setting, i.e. the Georgia Medicaid population. Secondly, this study forecasted the categorized antipsychotic prescription utilization through the year 2002. A dministrative claims data spanning 1990-1997 for Medicaid eligible persons suffering from schizophrenia in the state of Georgia were supplemented with psychiatric institutional data obtained from the Georgia Department of Hum an Resources. A total of 16 227 Medicaid-eligible recipients had a code ind icative of schizophrenia (ICD-9-CM = 295.**) and were at least 16 years of age at the time of their first diagnosis. The mean recipient prescription u se and expenditures were tallied for each month of the study and stratified by prescription category (atypical, clozapine. decanoate, and traditional antipsychotic). ARIMA time series models were identified and estimated usin g these monthly PMPM utilization and expenditures estimates to forecast 5 y ears beyond the last month of the study. The total use of antipsychotics in creased modestly throughout the study period, and the use of atypicals, clo zapine, and decanoate products increased substantially, while a decrease wa s observed for traditional antipsychotics. In 1995 dollars, antipsychotic e xpenditures increased from a mean of approximately $10 PMPM in 1990 to $95 projected for the year 2002. This transition from traditional oral antipsyc hotics to atypicals and decanoate products has a profound effect on drug ex penditures for systems paying for the care of persons with schizophrenia. F urther studies to determine the value of the transitions of therapy describ ed in this study need to be evaluated using a system-wide- or Medicaid pers pective. (C) 2001 Elsevier Science B.V. All rights reserved.