Adherence to Long-Acting Injectable Risperidone ISM in a Community Psychiatric Setting: A Real-World Observational Study
G. Cereda, A. Panariello, A. Galluzzo, D. Bortoletti, S. Giaretto, A. Vita, M. PercudaniIntroduction
Schizophrenia affects over 24 million people worldwide and is a leading cause of disability (Collaborators Eur Neuropsychopharmacol 2024; 93: 1-12).
Antipsychotics are the cornerstone of treatment, reducing symptoms and relapse (Leucht et al. Lancet 2012; 379: 2063-2074). Yet up to 50% of patients are non-adherent (Llorca et al. Eur Psychiatry 2013; 28: 1-8). As many as 60% discontinue after 3 months and 80% after 2 years, with a five-fold higher relapse risk in those who stop treatment (Leijala et al. BMC Psychiatry 2021; 21: 37). Long-acting injectables (LAIs) were developed to improve adherence and detect missed doses (Correll et al. CNS Drugs 2021; 35: 215-233). Risperidone ISM, a once-monthly LAI without oral supplementation, has proven efficacy in trials, but real-world data are scarce. Meta-analyses confirm LAIs reduce relapse and hospitalization compared with oral antipsychotics (Kishimoto et al. Lancet Psychiatry 2021; 8: 387-404).
Objectives
To assess adherence to risperidone ISM in a community psychiatric setting, comparing adherent and non-adherent patients, and evaluating rehospitalizations and outpatient visits.
Methods
This retrospective study included 44 patients who initiated risperidone ISM, all diagnosed with a psychotic spectrum disorder. Patients with fewer than three injections (n=10) or dropout within the first three injections (n=3) were excluded. The final sample comprised 31 patients. Adherence was defined as continuation without dropout (n=21). Non-adherence was defined as dropout after ≥4 injections (n=10). Demographic and clinical data were collected. Outcomes were rehospitalizations and outpatient visits, standardized by months of follow-up. Chi-square and Mann–Whitney U tests were used.
Results
No significant differences were found in age, sex, or substance use. Schizophrenia was more frequent among adherent patients compared with other psychotic spectrum disorders. Clinical outcomes are shown in Table 1: mean rehospitalization rates were low in both groups (0.022 vs 0.050 per month, p=0.56). Outpatient visits were more frequent among adherents (2.37 vs 2.07 per month), though not significant (p=0.11).
Demographic and clinical characteristics of the sample Table 1. Long description.