Antipsychotic prescribing patterns in Australia: a retrospective analysis

Abstract

Abstract Background To examine real-world patterns of antipsychotic use in patients with schizophrenia Australia. Methods This retrospective cohort analysis was conducted using the Australian Commonwealth Department of Human Services Pharmaceutical Benefits Scheme (PBS) 10% sample data. Included data were for patients aged 16-years or older who initiated treatment for the first time with a PBS-reimbursed antipsychotic medication for schizophrenia between July 2013 and September 2017. Patterns of treatment usage were summarised descriptively. Differences in prescribing patterns by age and prescribing year were reported. Treatment persistence was estimated using Kaplan-Meier methods, with differences explored using log-rank tests. Values of p < 0.05 were considered statistically significant. Results 6,740 patients, representing 8,249 non-unique patients, received prescriptions for antipsychotic medications. Patients were aged 16 years to over 85 years (54.5% were < 55 years) and two-thirds of patients were male (61%). The majority of treatment episodes (62%, n = 5,139/8,249) were prescribed an atypical oral antipsychotic. Typical long-acting antipsychotic therapies (LATs) were prescribed 19% of the treatment episodes (n = 1,608/8,249. There was a small increase in prescribing of atypical LAT and typical LAT and a small decrease in atypical oral and clozapine prescribing over the study period. Treatment persistence was greatest in patients treated with clozapine, than in those treated with atypical LATs. Conclusions While the majority of patients receive atypical antipsychotic medications, one in five continue to use older typical LAT therapies. Patient age and time on therapy may be associated with choice of therapy. Persistence to atypical LAT therapy is better than for other treatment modalities in this real-world cohort.