Increased risk of death compared to other antipsychotics in elderly clozapine users in Poland

Clozapine can cause severe adverse effects. Few epidemiologic studies have considered the effect of clozapine use in elderly patients. The aim of this study was to assess mortality in elderly patients treated with clozapine in comparison to patients treated with first- or second-generation antipsychotics. We conducted a retrospective cohort study involving 26 639 patients who were 65 years of age or older and were receiving antipsychotic medication between 2008 and 2012. Cox proportional-hazards models were used to compare the risk of death between different groups of antipsychotics after controlling for age, sex, concomitant treatment with cardiovascular or metabolic medications. The use of antipsychotic medications other than clozapine was associated with a lower adjusted risk of death [hazard ratio, 0.89; 95% confidence interval (95% CI), 0.79-0.99]. The use of cardiac and antilipemic but not antidiabetic drugs was associated with a significantly lower risk of death in this population (hazard ratio, 0.88; 95% CI, 0.83-0.93; hazard ratio, 0.66; 95% CI, 0.58-0.75 and hazarad ratio, 1.09; 95% CI, 0.96-1.24, respectively). These results suggest that clozapine is associated with an increased risk of death in the elderly. Although the study was based on administrative records linkage, its results suggest that attention should be paid to patients taking antipsychotics.