The impact of olanzapine, risperidone, or haloperidol on the cost of schizophrenia care in a medicaid population.
OBJECTIVE
The objective of this study was to assess the impact of medication treatment on Medicaid costs for persons with schizophrenia.


METHODS
Michigan Medicaid claims from January 1995 through September 1998 were analyzed for persons with schizophrenia diagnoses who initiated olanzapine (n = 458), risperidone (n = 481), or haloperidol (n = 252) treatment between January 1996 and September 1997. Total and component Medicaid payments were compared for the year after treatment initiation, with simultaneous adjustment for patient demographics, comorbid conditions, prior medication use, prior service use, and prior year costs.


RESULTS
Significant baseline differences existed between the groups in prior medication and service use. Adherence to index medication varied between the groups (O = 60%; R = 54%; H = 37%; P < =.01 for each pairwise comparison). Average postperiod costs were US dollars 14512 per subject. After baseline adjustment, there were no significant differences in mean total cost. Excluding index medication costs, the olanzapine group's average cost was significantly lower than risperidone (-US dollars 1791, P =.002) and haloperidol (-US dollars 2080, P =.003), whereas the risperidone and haloperidol groups were not significantly different. The differences were driven by significantly lower cost for inpatient services for other medications among the olanzapine group.


CONCLUSIONS
Total costs of schizophrenia care associated with olanzapine, risperidone, or haloperidol were similar, but component costs differed. Relative to risperidone or haloperidol, olanzapine may have a higher acquisition cost, but may decrease inpatient costs and be associated with more optimal medication use patterns. Use of risperidone may also increase pharmacy costs and be associated with greater persistence, relative to haloperidol.
Gibson
P Joseph
PJ
Health & Hospital Corporation of Marion County, Indianapolis, IN 46285, USA. JGibson@HHCorp.com
Damler
Robert
R
Jackson
E Anne
EA
Wilder
Teresa
T
Ramsey
Janet L
JL
D000328:Adult; D014150:Antipsychotic Agents / Q000191:economics*; D001569:Benzodiazepines / Q000191:economics* / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D016527:Drug Costs / Q000706:statistics & numerical data; D005260:Female; D006220:Haloperidol / Q000191:economics* / Q000627:therapeutic use; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D016018:Least-Squares Analysis; D016014:Linear Models; D008297:Male; D008484:Medicaid / Q000191:economics*; D008605:Mental Health Services / Q000191:economics / Q000706:statistics & numerical data; D008824:Michigan; D000077152:Olanzapine; D018967:Risperidone / Q000191:economics* / Q000627:therapeutic use; D012559:Schizophrenia / Q000188:drug therapy* / Q000191:economics*; D014481:United States
D014150:Antipsychotic Agents; D001569:Benzodiazepines; D006220:Haloperidol; D018967:Risperidone; D000077152:Olanzapine