Fig. 2

a Number of excess deaths per 100 patients for in-hospital mortality by non-adjusted, inverse probability of treatment weighted analysis and instrumental variable analysis. b Number of excess deaths per 100 patients for 24 h mortality by non-adjusted, inverse probability of treatment weighted (IPTW) analysis and instrumental variable (IV) analysis. We included age, gender, vital signs on arrival (systolic blood pressure, heart rate and Glasgow Coma Scale), Injury Severity Score and year of injury as covariate in both analyses