Clozapine reduces rehospitalization among schizophrenia patients

A number of studies have reported reduced rehospitalization for patients on clozapine. This article adds to that literature by mining the clozapine da tabase at Hillside Hospital. The sample consisted of 81 schizophrenia patie nts who entered Hillside on a typical neuroleptic and then had their medica tion changed to clozapine, We ascertained the number of inpatient hospitali zations before starting clozapine and compared this with the number of hosp italizations after starting clozapine. We also followed an age- and gender- matched comparison group of other schizophrenia patients who entered Hillsi de at approximately the same time. Results indicate that the mean number of rehospitalizations while on a typi cal neuroleptic was 2.03 (1.93)/year, whereas it was only .56 (.97)/year af ter the commencement of clozapine treatment; t(80)=5.78, p<.001. A 95% conf idence interval for the superiority of clozapine over standard neuroleptic treatment as measured in rehospitalizations/year is (1.0, 2.0). The decreas e in hospitalization rate of .4 (1.6)/year (pre-index date minus post-index date) for the comparison group was also statistically significant [t(80)=2 .3, p<.03]; the 95% confidence interval for this decrease over time is (.1, .8). The pre-post change was much greater for the clozapine patients than comparison patients. A 2x2 repeated measures analysis of variance (ANOVA) c ontrasting the comparison group to the clozapine patients both before and a fter the index date indicates a significant time by group interaction (F(1, 80)=22.35, p<.001), thus documenting the greater relative decrease in rehos pitalization rate in the clozapine group.