Antipsychotics deprescribing in schizophrenia: trends and associated characteristics in Belgium and Québec

Background : Antipsychotic polypharmacy (APP) is common worldwide in schizophrenia, while switch to antipsychotic monotherapy reduces adverse effects. Canada has been the leader in deprescribing policies in the last decades. Aims : To detect factors, including countries, associated with successful antipsychotic deprescribing after a psychiatric hospitalisation. Methods : Retrospective data were collected in a tertiary care hospital in Montreal (QC, Canada) and compared to data collected in 6 Belgian hospitals, in 2020-2021. Adult inpatients with a diagnosis of schizophrenia or schizoaffective disorder and discharged from a psychiatric unit after an acute hospitalisation were included. Results : At discharge, the daily number of antipsychotics had decreased in 22.2% of the 63 Canadian and 9.9% of the 516 Belgian patients, and increased in 17.5% of the Canadian and 24.3% of the Belgian patients. Living in a residential facility (OR=2.51, 95% CI 1.05-4.39), ≥2 previous antipsychotic trials (OR=15.38, 95% CI 3.62-65.36), having an antipsychotic side effect (OR=1.86, 95% CI 1.01-3.44), being in a general hospital (OR=2.28, 95% CI 1.09-4.75) and in Canada (OR=4.13, 95% CI 1.48-11.5) increased the odds of successful antipsychotic deprescribing at hospital discharge. Patients with a LAI (OR=0.51, 95% CI 0.26-0.98), prior clozapine use (OR=0.36, 95% CI 0.13-0.95), a greater antipsychotic exposure (OR=0.35, 95% CI 0.2-0.61) and a higher number of hypno-sedatives (OR=0.65, 95% CI 0.43-0.98) were less likely to have a deprescription. Conclusion : Antipsychotic deprescribing is feasible and already performed in identifiable patients, settings or situations. Patients hospitalised in Canada are more likely to have a deprescription than in Belgium