OBJECTIVES: To examine the change in the use of healthcare resources after administration of paliperidone palmitate once-monthly (PP1M)injection in patients with schizophrenia

METHODS: Retrospective comparison of the health care utilization and associated costs of pre- and post-PP1M treatment in 413 patients with schizophrenia recruited from 3 major public hospitals providing psychiatric services in Hong Kong. Patients were categorized into early treatment (<3yrs since diagnosis) and chronic (>3yrs) groups, and also whether they were receiving polypharmacy (POP).

RESULTS: Patients who were started on early therapy with no POP had the most favourable outcomes. For the overall cohort, there was a slight increase in annual in-patient days (IP) per patient and outpatient visit (OP) by 3.57 and 1.87 respectively, and a decrease in emergency room visit (ER) of 0.9 (p<0.05). For non-polypharmacy (NP) patients receiving early PP1M therapy, there was a significant decrease in IP and ER of 21.56 (p<0.05) and 1.15 (p<0.05) respectively but an increase in OP of 1.88 (p<0.05). For patients with POP, there was an all-across increase in IP and all-across decrease in OP and ER. In monetary terms, a NP patient receiving early therapy may have an overall cost avoidance of HKD40,878 (USD5,241, 1USD=7.8HKD) per year compared to a required yearly spending of HKD15,758 (USD2,020) per patient when therapy was given after 3 years. For patients with POP, there was an all-across increase in overall spending despite reductions in OP and ER. Analysis using multivariate linear regression based on generalized estimating equations and sensitivity analysis using linear mixed model supported the findings.

CONCLUSIONS: From the 413 patients studied, potential cost avoidance is possible by early administration of PP1M. Our study has provided real world evidence for early use of PP1M in patients with schizophrenia.