A traumatic tale of two cities: does EMS level of care and transportation model affect survival in patients with trauma at level 1 trauma centres in two neighbouring Canadian provinces?

BACKGROUND: Two distinct Emergency Medical Services (EMS) systems exist in Atlantic Canada. Nova Scotia operates an Advanced Emergency Medical System (AEMS) and New Brunswick operates a Basic Emergency Medical System (BEMS). We sought to determine if survival rates differed between the two systems.

METHODS: This study examined patients with trauma who were transported directly to a level 1 trauma centre in New Brunswick or Nova Scotia between 1 April 2011 and 31 March 2013. Data were extracted from the respective provincial trauma registries; the lowest common Injury Severity Score (ISS) collected by both registries was ISS≥13. Survival to hospital and survival to discharge or 30 days were the primary endpoints. A separate analysis was performed on severely injured patients. Hypothesis testing was conducted using Fisher's exact test and the Student's t-test.

RESULTS: 101 cases met inclusion criteria in New Brunswick and were compared with 251 cases in Nova Scotia. Overall mortality was low with 93% of patients surviving to hospital and 80% of patients surviving to discharge or 30 days. There was no difference in survival to hospital between the AEMS (232/251, 92%) and BEMS (97/101, 96%; OR 1.98, 95% CI 0.66 to 5.99; p=0.34) groups. Furthermore, when comparing patients with more severe injuries (ISS>24) there was no significant difference in survival (71/80, 89% vs 31/33, 94%; OR 1.96, 95% CI 0.40 to 9.63; p=0.50).

CONCLUSION: Overall survival to hospital was the same between advanced and basic Canadian EMS systems. As numbers included are low, individual case benefit cannot be excluded.