Cost-effectiveness of clozapine in patients with high and low levels of hospital use

Background: This study examined the relationship between pretreatment hospi tal use and the cost-effectiveness of clozapine in the treatment of refract ory schizophrenia. Methods: 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; m ean = 215 psychiatric hospital days in the year prior to study entry) and t hose with few days in the hospital use (hereafter, low hospital users) (n = 282; mean = 58 hospital days). Analyses were conducted with the full inten tion-to-treat sample (n = 423) and with crossovers excluded (n = 291). Results: 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 medicat ions and other health services, costs were $7134 less than for controls amo ng high hospital users (P = .14) but only $759 less than for controls among low hospital users (P = .82). Clinical improvement in the domains of sympt oms, quality of life, extrapyramidal symptoms, and a synthetic measure of m ultiple outcomes favored clozapine in both high and low hospital user group s. Conclusions: Substantial 1-year cost savings with clozapine are observed on ly among patients with very high hospital use prior to initiation of treatm ent while clinical benefits are more similar across groups. Cost-effectiven ess evaluations, and particularly studies of expensive treatments, cannot b e generalized across type of use groups.