Comparative effectiveness of depot and oral second generation antipsychotic drugs in schizophrenia: A nationwide study in Hungary

We conducted a nationwide, full-population based investigation to evaluate the comparative effectiveness of all marketed second generation antipsychotic drugs (SGA) prescribed for outpatients with the diagnosis of schizophrenia in Hungary. Using the national central register, our observational follow-up study included all patients with schizophrenia or related disorder between 01/01/2006 and 30/06/2008. The study cohort comprised 9567 patients who started new SGA during the inclusion period (01/07/2007-30/06/2008). All-cause medication discontinuation of 8 SGAs (1 depot and 7 oral formulations) marketed during the inclusion period, and the time to all-cause discontinuation were the main outcomes. Statistical models included the Kaplan-Meier and the Cox proportional hazards models with propensity score adjustment. Patients treated with a depot formulation risperidone had the longest time to discontinuation with a median of 215 days (95%CI:181-242 days), which was statistically significantly different compared to patients treated with the rest of the medications: olanzapine (136 days, 95%CI:121-153 days), aripiprazole (102 days, 95%CI:81-126 days), ziprasidone (93 days, 95%CI:82-119 days), quetiapine (89 days, 95%CI:81-100 days), clozapine (76 days, 95%CI:54-92 days), amisulpride (73 days, 95%CI:62-85 days), and risperidone (55 days, 95%CI: 41-63 days). Our results in Hungary are partly similar to those of a recent register-based study in Finland with patients who were discharged from their first hospitalization for schizophrenia (Tiihonen et al., 2006, Tiihonen et al., 2011); namely the median times to all-cause medication discontinuation were <120 days for the majority of the oral SGA. In terms of medication differences, our data support the superior effectiveness of the depot formulation regarding all-cause discontinuation, followed by olanzapine at the efficacy rank order.