Denominator Matters: Comparing the Impact of Estimated Resident Population Versus Medicare Enrolment Population on Healthcare Utilisation Analyses

Nationally, differences between healthcare utilisation rates calculated using ABS ERP versus Medicare enrolment data were minimal. ERP-based rates were lower for younger adults, while Medicare-based rates were lower for older adults. SO WHAT?: Our findings emphasise the importance of carefully selecting and reporting denominators, considering their relevance to the population targeted by the service to ensure meaningful interpretation.