Factors related to improvement of symptoms, function, and caregiver burden in Chinese patients with schizophrenia after switching to paliperidone palmitate once-monthly from oral antipsychotics

Background: Paliperidone palmitate once-monthly (PP1M) demonstrated symptomatic and functional remission in patients with schizophrenia. This post hoc analysis aimed to identify factors associated with improved clinical outcomes in patients switching to PP1M (75-150 mg eq.). Methods: The improved patient outcomes were observed as Positive and Negative Symptom Scale (PANSS, symptoms) score < 70: 66.7% (407/610), Personal and Social Performance (PSP, function) score > 70:34.3% (199/581), and Involvement Evaluation Questionnaire (IEQ, caregiver burden) reduction >= 6:50.2% (270/538). Independent variables including demographics, disease duration, employment status, and clinical scores were screened individually using a univariate analysis and subsequently, variables (cutoff p < 0.15) were analyzed using a multivariate regression analysis for association with better clinical outcomes at week 13. Results: The factors significantly associated with favorable clinical outcomes were reduction in PANSS at week 5 (odds ratio [OR]=1.14, 95% CI=1.11-1.17) with symptom reduction; baseline PSP total score (OR=1.07, 95% CI=1.05-1.10), PSP change at week 5 (OR=1.07, 95% CI=1.05-1.10), PANSS reduction at week 5 (OR=1.06, 95% CI=1.03-1.08) with functional improvement, reduction in PANSS at week 5 (OR=1.02, 95% CI=1.01-1.03), and total IEQ score at baseline (OR=1.09, 95% CI=1.07-1.11) with caregiver burden reduction. Conclusion: Thus, symptom and functional improvements with caregiver burden reduction were observed in patients, and PANSS reduction at week 5 was commonly associated with favorable outcomes.