Treatment retention rates of 3-monthly paliperidone palmitate and risk: A population-based cohort study

Background: Limited evidence exists regarding real-world 3-monthly paliperidone palmitate (PP3M) treatment retention and associated factors.
Method: We conducted a retrospective, nationwide cohort study using the Taiwan National Health Insurance Research Database between October 2017 and December 2019. Adult patients with schizophrenia initiated on PP3M were enrolled. The primary outcomes were time to PP3M discontinuation and the proportions of patients receiving the next PP3M dose within 120 days among first-, second-, and third-dose completers. Key covariates included prior PP1M duration and adequate PP3M initiation, defined as PP1M for ≥4 months, with the final two PP1M treatments administered at the same dose, which is also an appropriate PP3M initiation dose.
Results: The PP3M treatment retention rates were 79.7%, 66.3%, and 52.5% after 6, 12, and 24 months, respectively, with 86.4%, 90.6%, and 90.0% of respective first-, second-, and third-dose completers receiving the next PP3M dose. Adequate PP3M initiation and prior PP1M treatment duration >180 days were associated with favorable PP3M treatment retention. In multivariate analyses, PP1M durations of 180–360 days (adjusted relative risk [aRR]=1.76) or Conclusions: Prior PP1M duration and adequate PP3M initiation are major factors affecting PP3M treatment retention. Patients with a PP1M duration of 180–360 days had a mildly increased risk of PP3M discontinuation at the second dose, but their 2-year treatment retention rate was similar to those with a PP1M duration >360 days.