Cost-effectiveness of olanzapine vs. aripiprazole in the treatment of schizophrenia.
OBJECTIVE
Information about the cost-effectiveness of aripiprazole relative to other atypical antipsychotics in the treatment of patients with schizophrenia is limited. This information is needed to better inform drug formulary managers and population-based health care decision makers. The objective of this study was to compare the cost-effectiveness of olanzapine to aripiprazole in the treatment of schizophrenia from the perspective of public payers in the United States.


METHODS
Data for this post-hoc analysis came from a 28-week double-blind, randomized trial of individuals with schizophrenia who were treated with olanzapine or aripiprazole (clinicaltrial.gov identifier NCT00088049). Two-thirds (67.7%) of the patients were male and the patients' mean age was 37.6 years. Utilities were calculated based on previously published methods using the Positive and Negative Syndrome Scale (PANSS) and treatment-emergent adverse events. Treatment costs were calculated based on previously published methods and were inflated to 2008 US dollars. A mixed model was used to compare outcomes on utilities. Propensity score-adjusted analysis of covariance was used for the cost analysis.


RESULTS
Olanzapine treatment was associated with statistically significantly greater total utility scores relative to aripiprazole (0.78 vs. 0.76; p = 0.024) and lower total treatment costs ($22,831 vs. $24,749; p = 0.013), although medication acquisition cost was significantly higher for olanzapine than aripiprazole ($3524 vs. $2637; p < 0.001). An incremental cost-effectiveness ratio was not calculated because olanzapine was found to be the dominant choice (i.e., greater effectiveness and lower total costs).


CONCLUSIONS
This cost-effectiveness analysis is the first to use patient-level data from a randomized, double-blind study comparing olanzapine and aripiprazole in the treatment of patients with schizophrenia. Olanzapine was found to be a dominant cost-effective choice, as it was associated with greater effectiveness at lower total costs relative to aripiprazole.
Eli Lilly and Company, Lilly Corporate Center, DC 4133, Indianapolis, IN 46285, USA. haya@lilly.com
Haya
H
Ascher-Svanum
Michael D
MD
Stensland
Xiaomei
X
Peng
Douglas E
DE
Faries
Virginia L
VL
Stauffer
Olawale O
OO
Osuntokun
John M
JM
Kane
D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000191:economics / Q000627:therapeutic use; D000068180:Aripiprazole; D001569:Benzodiazepines / Q000191:economics* / Q000627:therapeutic use*; D003362:Cost-Benefit Analysis; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D000077152:Olanzapine; D010879:Piperazines / Q000191:economics* / Q000627:therapeutic use*; D015363:Quinolones / Q000191:economics* / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic / Q000191:economics / Q000379:methods; D012189:Retrospective Studies; D012559:Schizophrenia / Q000188:drug therapy* / Q000191:economics; D016896:Treatment Outcome; D014481:United States; D055815:Young Adult
D014150:Antipsychotic Agents; D010879:Piperazines; D015363:Quinolones; D001569:Benzodiazepines; D000068180:Aripiprazole; D000077152:Olanzapine