Healthcare Pattern of Use Before and After Initiating a Long-Acting Antipsychotic Among a Cohort of 6221 Patients With a History of Psychosis.

ObjectiveTo evaluate changes in antipsychotic treatment patterns and healthcare utilization before and after initiation of long-acting injectable antipsychotics (LAI-APs) in a large Québec population cohort, comparing individuals with schizophrenia (SCZ) to those with other psychotic disorders (non-SCZ).MethodWe conducted a retrospective cohort study using linked Québec administrative databases (RAMQ, MED-ECHO, and public drug insurance) to identify 6,221 adults who initiated a LAI-AP between April 2013 and December 2016, after a 12-month LAI-free period. Participants were followed for 12 months before and after the index date. The cohort was stratified into SCZ and non-SCZ, and were further divided by regimen at initiation (LAI only; LAI + clozapine; LAI + other oral antipsychotic). Antipsychotic exposure and health-service usage (hospitalizations, emergency visits, outpatient and community care) trajectories were analyzed weekly using state-sequence analysis; pre- versus post-initiation comparisons used paired statistical tests.ResultsOf 6,221 patients (63.4% male; mean age 41.6 years), initial treatments consisted of paliperidone LAI (55.7%), aripiprazole LAI (21.5%), risperidone LAI (6.9%), first-generation LAI (15.6%), and LAI combinations (0.2%); 40% received LAI only, 5% LAI + clozapine, 55% LAI + an oral antipsychotic. SCZ patients were more often male, economically disadvantaged, and more likely to receive clozapine. After LAI initiation, hospital days fell sharply by almost 70% and outpatient and community-care visits increased substantially. Use of oral antipsychotics decreased overall post-initiation, except for clozapine (which rose) and first-generation oral drugs (which remained stable).ConclusionsIn this real-world Québec cohort, LAI-AP initiation was followed by a marked reduction in hospitalizations and a shift toward outpatient and community care, regardless of diagnosis. Observed differences in sociodemographic and clinical profiles between SCZ and non-SCZ patients-and among SCZ treatment subgroups-suggest the need for tailored care pathways. These findings support LAI-AP effectiveness in reducing healthcare utilization and inform resource planning.