Acknowledgement
The authors thank the following institutions for providing the data used in this study. Staff at the WA Data Linkage Branch and data custodians of the WA Department of Health for access to and provision of the State linked data (Hospital Morbidity Data Collection, Emergency Department Data Collection and Death Registrations). The Australian Department of Health for the cross-jurisdictional linked PBS data. The people of Western Australia whose data were used in this study.
Ethical approval and consent
Ethics approval obtained from the Western Australia Department of Health Human Research Ethics Committee (EC00422). The study was conducted according to the principles of the Declaration of Helsinki.
Author contributions
GD and FS conceived the study. JS, TR and FS conducted the study and collected and analysed the data. JS, AS and BJ wrote the first draft of the manuscript. All co-authors critically revised the manuscript and gave final approval and agree to be accountable for all aspects of the work ensuring integrity and accuracy.
Disclosure statement
BJ consults for Artrya Pty Ltd. GD received speaker bureau fees for Pfizer, Johnson and Johnson, Amgen, conference sponsorship from Bayer and consults and has equity interest in Artrya Pty Ltd. JS, AS, TR and FS report no disclosures related to this study.