Factors related to the comparative effectiveness of clozapine in patients with schizophrenia.

AIM: To examine the factors related to the comparative effectiveness of clozapine.

PATIENTS & METHODS: US insurance claims databases were used to identify schizophrenia patients. To examine the factors modifying the comparative effectiveness of clozapine in relation to other second-generation antipsychotics, a series of variables were interacted with a clozapine indicator in regressions.

RESULTS: The impacts of clozapine on both persistence and adherence were significantly modified by prior hospitalization, prior epilepsy diagnosis and prior use of antianginal agents. The relative risks of heavy inpatient services use and heavy emergency department services use were also modified by several factors.

CONCLUSION: Several factors can be used to identify patients who are more likely to benefit from clozapine than other second-generation antipsychotics.