Investigation on the factors associated with maintenance of paliperidone long-acting injection in the real-world treatment of patients with schizophrenia.

Background: Long-acting injectable (LAI) antipsychotics have been shown to improve adherence and clinical outcomes in schizophrenia treatment. However, issues with compliance and early discontinuation of LAIs remain a significant challenge in real-world settings. Understanding the factors influencing successful initiation and maintenance is essential to maximize their clinical benefits.

Objectives: This study aimed to investigate factors associated with the maintenance of paliperidone LAI (PLAI) during the first year of treatment in a real-world clinical setting, focusing on initiation practices and baseline clinical factors.

Design: This was a non-interventional, retrospective observational study conducted at three hospitals in South Korea. Data were collected from electronic medical records from January 2010 to January 2023.

Methods: This study included 664 patients who initiated PLAI treatment. Kaplan-Meier survival analysis and multivariate Cox proportional hazards models were used to evaluate clinical and demographic factors influencing the 1-year discontinuation rate.

Results: The 1-year discontinuation rate was 51.5% (342/664), with most discontinuations occurring in the early phase of treatment. Factors significantly associated with a lower risk of discontinuation included initiating PLAI with the standard starting dose of 150 mg (hazards ratio (HR) 0.766, p = 0.021), concurrent use of antipsychotics at baseline (HR 0.630, p = 0.019), a higher dose of concurrent antipsychotics (HR 0.985, p = 0.005), and outpatient initiation (HR 0.671, p < 0.001). Baseline clozapine use was associated with a lower risk of treatment discontinuation (HR 0.755, p = 0.096). A predictive model incorporating these factors demonstrated moderate ability to predict 1-year discontinuation (area under the curve (AUC) = 0.61).

Conclusion: The findings highlight the importance of adhering to the standard dosing regimen for PLAI initiation and its potential as an augmentation agent in combination with other antipsychotics. Initiating PLAI in an outpatient setting and addressing adherence challenges early in treatment may enhance long-term treatment continuity in patients with schizophrenia.