Effectiveness of injectable risperidone long-acting therapy for schizophrenia: data from the US, Spain, Australia, and Belgium

BACKGROUND Because wide variations in mental health care utilization exist throughout the world, determining long-term effectiveness of psychotropic medications in a real-world setting would be beneficial to physicians and patients. The purpose of this analysis was to describe the effectiveness of injectable risperidone long-acting therapy (RLAT) for schizophrenia across countries. METHODS This was a pragmatic analysis of data from two prospective observational studies conducted in the US (Schizophrenia Outcomes Utilization Relapse and Clinical Evaluation [SOURCE]; ClinicalTrials.gov registration number for the SOURCE study: NCT00246194) and Spain, Australia, and Belgium (electronic Schizophrenia Treatment Adherence Registry [eSTAR]). Two separate analyses were performed to assess clinical improvement during the study and estimate psychiatric hospitalization rates before and after RLAT initiation. Clinical improvement was evaluated using the Clinical Global Impressions-Severity (CGI-S) and Global Assessment of Functioning (GAF) scales, and change from baseline was evaluated using paired t tests. Psychiatric hospitalization rates were analyzed using incidence densities, and the bootstrap resampling method was used to examine differences between the pre-baseline and post-baseline periods. RESULTS The initial sample comprised 3,069 patients (US, n = 532; Spain, n = 1,345; Australia, n = 784; and Belgium, n = 408). In all, 24 months of study participation, completed by 39.3% (n = 209), 62.7% (n = 843), 45.8% (n = 359), and 64.2% (n = 262) of patients from the US, Spain, Australia, and Belgium, respectively, were included in the clinical analysis. Improvements compared with baseline were observed on both clinical assessments across countries (P < 0.001 at all post-baseline visits). The mean improvement was approximately 1 point on the CGI-S and 15 points on the GAF. A total of 435 (81.8%), 1,339 (99.6%), 734 (93.6%), and 393 (96.3%) patients from the US, Spain, Australia, and Belgium, respectively, had ≥1 post-baseline visit and were included in the analysis of psychiatric hospitalization rates. Hospitalization rates decreased significantly in all countries regardless of hospitalization status at RLAT initiation (P < 0.0001) and decreased significantly in the US and Spain (P < 0.0001) when the analysis was limited to outpatients only. CONCLUSIONS RLAT in patients with schizophrenia was associated with improvements in clinical and functional outcomes and decreased hospitalization rates in the US, Spain, Australia, and Belgium, despite differences in health care delivery systems.