Comparison of Paliperidone Palmitate and Risperidone Long-Acting Injection in Schizophrenic Patients: Results From a Multicenter Retrospective Cohort Study in France.

Purpose/background: The study objective was to compare the impact of being treated by paliperidone palmitate (PP) or risperidone long-acting injection (RLAI) on the length of stay on initial hospitalization, rehospitalization risk, and treatment duration in schizophrenic patients.

Methods: We conducted an observational retrospective cohort study in 43 centers in France, including schizophrenic patients who initiated a treatment by PP or RLAI during initial hospitalization. The follow-up periods started in September 2012 for the RLAI group (median follow-up duration, 233 days) and in June 2013 for the PP group (259 days). Statistical analyses were based on Cox regression models, with propensity score weighting to account for differences in patients' characteristics.

Findings/results: The analysis included 347 patients: 197 in the PP treatment group and 150 in the RLAI group. Compared with patients on RLAI, patients on PP were significantly more likely to have nonpsychiatric comorbidities, to have been on previous antipsychotic therapy, or to have been hospitalized for psychiatric care in the previous year. With regard to length of stay on initial hospitalization, there was no statistically significant difference between both groups (hazard ratio, 1.13 [0.97; 1.31]). Being on PP was associated with similar times to first rehospitalization compared with RLAI (hazard ratio, 0.92 [0.65; 1.30]).

Implications/conclusions: We observed nonsignificant differences in initial hospitalization duration and time to rehospitalization between PP and RLAI, potentially due to lack of statistical power. A trend was observed in favor of PP with regard to time to treatment discontinuation, although this result was compromised by patients who switched between RLAI and PP.