Rehospitalization risk in community-dwelling schizophrenia patients receiving paliperidone palmitate: a retrospective cohort study in urban China.

BACKGROUND: While long-acting injectable paliperidone palmitate (PP-LAI) improves treatment adherence in schizophrenia, rehospitalization risks persist under community management. This study identified factors influencing rehospitalization in community-dwelling schizophrenia patients receiving PP-LAI. METHODS: A retrospective cohort study included 560 patients from 124 communities in Shenzhen (16 September 2022-15 September 2024). Data were extracted from medical databases. The primary outcome was rehospitalization due to psychiatric relapse. Multivariate Cox regression models were used to identify independent risk factors, adjusting for covariates including age, gender, marital status, employment, guardian relationship, pre-study hospitalization history, treatment phase, and concomitant antipsychotic use. RESULTS: During a median follow-up of 14 months, 50 patients (8.93%) were rehospitalized (rate: 7.83 per 100 person-year). Treatment discontinuation (n = 133) was primarily due to adverse drug reactions (30.08%) and disease relapse (31.58%). Cox analysis identified guardian type (parents vs. spouse: HR = 2.14, 95% CI: 1.05-4.37), pre-study hospitalization history (yes vs. no: HR = 2.69, 95% CI: 1.50-4.81), and treatment discontinuity (discontinuation vs. regular treatment: HR = 8.61, 95% CI: 2.61-28.35) as independent risk factors for rehospitalization. CONCLUSIONS: Sensitivity analysis suggested that the elevated risk was substantially driven by patients who discontinued treatment due to disease relapse, indicating a complex interplay between discontinuation and outcome. Prior hospitalization and guardianship by parents also significantly increase risks. Clinical strategies should prioritize maintaining treatment continuity, proactively managing side effects, and strengthening family/community support for high-risk groups to reduce the risk of rehospitalization. TRIAL REGISTRATION: Not applicable. (This is a retrospective observational study and does not involve a clinical trial requiring prospective registration).