Cross tabulation of demographic characteristics of included and excluded patients.*

*Values are expressed as medians (range:IQR) or proportions (%) where appropriate. Abbreviations: GA = General Anaesthesia; ICISS = ICD-derived Injury Severity Score; LOS = Length of Hospital Stay. 1Excluded due to coding errors; 2Excluded because patients where either transferred or died before discharge 3Defined as ICISS4Defined as major surgery (such as brain or spine, thoracic, abdominal, neck, vascular, debridement under GA, or critical orthopaedic surgery) or blood transfusion; 5According to either serious injury or resource use definition.