Use of pharmacy data to assess quality of pharmacotherapy for schizophrenia in a national health care system: individual and facility predictors.

OBJECTIVES: This paper presents a profile of the use of antipsychotic medications in the treatment of schizophrenia in a national health system.
METHODS: Prescription drug records written for antipsychotic medications between June 1999 and September 1999 were collected for patients diagnosed with schizophrenia in the Department of Veteran Affairs (VA). Indicators were constructed describing whether patients received multiple antipsychotic medications and whether the total weekly dose was outside of the range specified in the treatment recommendations developed by the schizophrenia Patient Outcomes Research Team (PORT). Generalized estimation equations were used to identify patient and facility characteristics that are associated with adherence to PORT recommendations.
RESULTS: Of the 34,925 patients in the final sample, 2,383 (6.8%) received prescriptions for more than one antipsychotic (polypharmacy). A higher number of patients (4,554 or 13.0%) were dosed above the PORT recommendations on an antipsychotic medication and even more (8,148 or 23.3%) were dosed below the recommended PORT dosage. Older patients, minorities, and those with comorbid depression or substance abuse were generally less likely to receive multiple antipsychotics or be dosed above PORT recommendations. Neither academic emphasis (the percentage of the mental health budget spent on research and education) nor fiscal stress was significantly associated with adherence to recommendations.
CONCLUSIONS: In the nation's largest mental health system, a relatively small number of patients were prescribed multiple antipsychotic medications, but more than a third were dosed outside of the PORT recommended range.