2.2 | Study measures
Outcomes of interest included the dispensing of antipsychotic
medications, antidepressants, anxiolytics, and hypnotics. The PBS item
code of each medication dispensed between 2013 and 2022 was linked to
the following Anatomical Therapeutic Chemical (ATC) codes: N05A for
antipsychotics, N06A for antidepressants, N05B for anxiolytics, and N05C
for hypnotics.6 We stratified age into the following
groups: 0-9, 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, 80-89, and
≥ 90 years. Sex was recorded as male or female. We used published
estimates for the fraction of the population dispensed medications
during the 2020-2021 period:7 0-9 years, 45.9%;
10-19, 45.9%; 20-29, 54.4%; 30-39, 57.5%; 40-49, 65.7%; 50-59,
69.1%; 70-79, 92.4%; 80-89, 98.0%; ≥ 90 years, 99.0%.