We investigated persons with injury aged at least 18 years who were included in two Australian registries – that is, the Victorian State Trauma Registry16,17 and the Victorian Orthopaedic Trauma Outcomes Registry15 –in the United Kingdom Burden of Injury Study in the United Kingdom of Great Britain and Northern Ireland,18 the Prospective Outcomes of Injury Study in New Zealand,14 the National Study on Costs and Outcomes of Trauma in the United States of America13 and the Dutch Injury Patient Survey in the Netherlands.12