Temporal trends of antipsychotic utilization patterns in 62,607 patients with schizophrenia-spectrum disorders in...

Antipsychotics are the mainstay treatment for schizophrenia-spectrum disorders (SSD). Existing data on real-world antipsychotic utilization patterns were primarily derived from Western countries and disregarded specific psychiatric diagnosis. There is limited research in Asia in this respect. This population-based study identified 62,607 patients aged ≥18-years with an SSD diagnosis who redeemed at least one antipsychotic prescription within 2006-2016, using data from health-record database of Hong-Kong public healthcare-services. We calculated annual prescription rates (per 1000 persons) for any antipsychotic, antipsychotic drug-classes (first- or second-generation-antipsychotics, FGAs or SGAs), formulations (oral or long-acting injectable, LAI), and individual antipsychotics. Joinpoint-regression analyses were performed to assess temporal antipsychotic prescription trends, quantified by average-annual-percent-change (AAPC), with 95% confidence-intervals (CIs). Result showed that overall antipsychotic prescription rate declined over time from 84.7% in 2006 to 79.9% in 2016. Oral-SGA use gradually surpassed oral-FGA use, rising from 23.8% in 2006 to 54.1% in 2016. LAI-use was relatively low in prevalence and significantly, albeit modestly, dropped from 23.7% to 18.8% over 11 years (AAPC: -2.20[-2.50 to -1.09]), but LAI-SGA use raised over time (APPC: 12.96 [6.59-19.70]), mainly driven by paliperidone-LAI. Risperidone and olanzapine represented two most frequently-prescribed oral-SGAs, while clozapine prescription rate was generally low (4.3%-6.1%), but showed significant upward trend (AAPC: 3.36[2.95-3.78]) over the study period. Our results affirm significant rising trend of SGA prescription over time. Yet, clozapine and LAIs remained relatively underutilized, indicating discrepancies between clinical-treatment recommendations and real-world prescribing practices. Further investigation is needed to clarify barriers to guideline-concordant practices to optimize treatment outcome.