2051. Use of System-Wide Outcomes Monitoring Data to Compare the Effectiveness of Atypical Neuroleptics

Objectives: This study used national VA administrative databases to examine changes in GAF scores associated with the use of atypical neuroleptics in a large sample of patients diagnosed with schizophrenia. The study was designed to examine changes in GAF ratings in both patients maintained on the same neuroleptic and in those that experienced a change of neuroleptic. In addition, among patients who switched neuroleptics, changes in GAF ratings associated with switching to each of the atypical neuroleptics commercially available in 2000 were also examined.

Methods: VA national administrative data were used to identify patients: 1) diagnosed with schizophrenia, 2) prescribed the same antipsychotic medication over a three month “stable medication” index period in 1999, and 3) for whom Global Assessment of Functioning (GAF) ratings were available from both the index period and the following year (n=9,066). Analysis of covariance, including potentially confounding factors, was used to compare change in GAF scores between patients maintained on the same medication and patients who were switched during the next year and, among those switched, between those switched to conventional and to each of the four then available atypical neuroleptics.

Results: Comparing the last GAF of the stable period to the last GAF of the subsequent (follow up) year, patients who remained on the same medication (7,157; 78.9%) showed improved GAF scores while patients who switched (1,909; 21.1%) demonstrated a decline (+0.6% vs. –3.7%, F=18.3; df=1,9065; p<.0001). Among the 1909 patients who switched medications, comparisons of the average GAF change according to the medication to which the patient was switched revealed no significant differences (F=0.22, df=4, 1875, p=0.93)

Conclusions: In this large administrative database patients with schizophrenia who switched neuroleptic medications showed significantly less improvement on clinician-rated GAF scores than patients maintained on their original medication. There were no significant differences between clozapine, olanzapine, risperidone, and quetiapine in change in GAF scores once patients were switched to these medications.

Impact: In a sample of 1909 patients, a global and widely accepted, although somewhat limited, measure of functioning failed to demonstrate any significant differences in improvement in patients switched to any of the then available atypical neuroleptics. While this is not a definitive assessment of these medications, it is one of the few based on real-world practice. If validated in other studies, these results would suggest that, in the absence of demonstrable differences in effectiveness among the atypical neuroleptics, other issues such as side effect burden or cost may play a prominent role in evaluating the utility of switching neuroleptics. In addition, this study demonstrates that it is possible to collect meaningful outcome data in large healthcare organizations and to use such data to investigate substantive clinical questions.