J Trauma Acute Care Surg. 2019 Oct;87(4):978-989

# Influence of prehospital physician presence on survival after severe trauma: Systematic review and meta-analysis.

Knapp J, Häske D, Böttiger B, Limacher A, Stalder O, Schmid A, Schulz S, Bernhard M.

BACKGROUND: As trauma is one of the leading causes of death worldwide, there is great potential for reducing mortality in trauma patients. However, there is continuing controversy over the benefit of deploying emergency medical systems (EMS) physicians in the prehospital setting. The objective of this systematic review and meta-analysis is to assess how out-of-hospital hospital management of severely injured patients by EMS teams with and without physicians affects mortality.

METHODS: PubMed and Google Scholar were searched for relevant articles, and the search was supplemented by a hand search. Injury severity in the group of patients treated by an EMS team including a physician had to be comparable to the group treated without a physician. Primary outcome parameter was mortality. Helicopter transport as a confounder was accounted for by subgroup analyses including only the studies with comparable modes of transport. Quality of all included studies was assessed according to the Cochrane handbook.

RESULTS: There were 2,249 publications found, 71 full-text articles assessed, and 22 studies included. Nine of these studies were matched or adjusted for injury severity. The odds ratio (OR) of mortality was significantly lower in the EMS physician-treated group of patients: 0.81; 95% confidence interval (CI): 0.71-0.92. When analysis was limited to the studies that were adjusted or matched for injury severity, the OR was 0.86 (95% CI, 0.73-1.01). Analyzing only studies published after 2005 yielded an OR for mortality of 0.75 (95% CI, 0.64-0.88) in the overall analysis and 0.81 (95% CI, 0.67-0.97) in the analysis of adjusted or matched studies. The OR was 0.80 (95% CI, 0.65-1.00) in the subgroup of studies with comparable modes of transport and 0.74 (95% CI, 0.53-1.03) in the more recent studies.

CONCLUSION: Prehospital management of severely injured patients by EMS teams including a physician seems to be associated with lower mortality. After excluding the confounder of helicopter transport we have shown a nonsignificant trend toward lower mortality.

LEVEL OF EVIDENCE: Systematic review and meta-analysis, level III.