Cost-effectiveness of Clozapine in Patients With High and Low Levels of Hospital Use

This study examined the relationship between pretreatment hospital use and the cost-effectiveness of clozapine in the treatment of refractory schizophrenia. Data from a 15-site randomized clinical trial were used to compare clozapine with haloperidol in hospitalized Veterans Affairs patients with refractory schizophrenia (n = 423). Outcomes were compared among those with many days in the hospital use (hereafter, high hospital users) (n = 141; mean = 215 psychiatric hospital days in the year prior to study entry) and those with few days in the hospital use (hereafter, low hospital users) (n = 282; mean = 58 hospital days). Analyses were conducted with the full intention-to-treat sample (n = 423) and with crossovers excluded (n = 291). Clozapine treatment resulted in greater reduction in hospital use among high hospital users (35 days less than controls, P =. 02) than among low users (21 days less than controls, P =. 05). Patients taking clozapine also had lower health care costs; after including the costs of both medications and other health services, costs were 7134 less than for controls among high hospital users (P =. 14) but only 759 less than for controls among low hospital users (P =. 82). Clinical improvement in the domains of symptoms, quality of life, extrapyramidal symptoms, and a synthetic measure of multiple outcomes favored clozapine in both high and low hospital user groups. Substantial 1-year cost savings with clozapine are observed only among patients with very high hospital use prior to initiation of treatment while clinical benefits are more similar across groups. Cost-effectiveness evaluations, and particularly studies of expensive treatments, cannot be generalized across type of use groups.