Cost comparisons of olanzapine and risperidone in treating schizophrenia

Objective: To review the literature on the healthcare costs associated with olanzapine and risperidone in treating schizophrenia. Data Sources and Study Selection: Published English-language pharmacoeconomic studies on olanzapine and risperidone obtained through a MEDLINE search (1990-May 2003) were selected. Additional studies were identified from a manual search of the references of retrieved articles. Data Extraction: Based on the identified studies, data were extracted on various treatment costs associated with the use of antipsychotic drugs, concomitant drugs from other classes, inpatient care, outpatient care, and emergency care. Emphasis was placed on studies directly comparing olanzapine and risperidone. Data Synthesis: Both olanzapine and risperidone were generally associated with a trend of decrease in total medical costs compared with typical antipsychotics. When directly comparing the drugs, some studies found significant cost savings in favor of olanzapine and some suggested risperidone to save total costs. Still others showed no significant difference in total costs between the 2 drug regimens. Conclusions: While both olanzapine and risperidone appear to be more cost saving than typical antipsychotics, the literature offers no conclusive evidence to determine the comparative advantage of one versus another in terms of total cost outcomes. Major factors that contribute to the inconclusive findings may include across-study variations in populations, design, outcome measures, dosage, severity of illness, inclusion criteria, and statistical methodologies.