The Impact of Paliperidone Palmitate on Hospitalization in Patients with Schizophrenia: A Retrospective Mirror-image Study

Objective: Whether long-acting injectable antipsychotics (LAI) are superior to oral antipsychotics remains a controversial question, and results vary depending on the study design. Our study was performed to compare outcomes of oral anti-psychotics and paliperidone palmitate (PP) in clinical practice by investigating the numbers of admissions and bed days. Methods: We performed a retrospective observational mirror-image study at a single medical center, reviewing medical charts to obtain the clinical data. Forty-six patients with a diagnosis of schizophrenia or schizoaffective disorder who had received at least two doses of PP were included in the analysis. The Wilcoxon signed-rank test was used to compare the numbers of bed days and admissions 1 year before starting PP with those numbers at 1 year after. Results: The mean number of admissions fell from 0.83 to 0.17 per patient (p < 0.0002), and the median fell from 1 to 0. The mean number of bed days decreased significantly, from 24.85 to 8.74 days (p < 0.006). The outcomes remained similar in sensitivity analyses set up with different mirror points. Conclusion: Our results indicate that initiating PP reduced the mean numbers of hospital admissions and bed days compared with prior oral medication. LAIs may thus be cost effective in practice; its use bringing about cost reductions greater than its purchase cost.