Impact of Physician-staffed Helicopters on Pre-hospital Patient Outcomes: A systematic review.

Background: Management of pre-hospital patients remains a challenge. In developed countries a physician-staffed helicopter emergency medical service (PS-HEMS) is used in addition to ground emergency medical service (GEMS), but the effect is debated. This systematic review aimed to evaluate the effect of PS-HEMS compared with GEMS on patient outcomes based on the published scientific literature.

Methods: Medline, EMBASE and the Cochrane Library were systematically searched on November 15, 2019 for prospective, interventional studies comparing outcomes of patients transported by either PS-HEMS or GEMS. Outcomes of interest were mortality, time to hospital and quality of life.

Results: The majority of 18 studies included were observational and difficult to summarize because of heterogeneity. Meta-analysis could not be carried out. Three studies found reduced mortality in patients transported by PS-HEMS compared with GEMS with Odds ratios (OR) of 0.68 (0.47-0.98); 0.29 (0.10-0.82) and 0.21 (0.06-0.73) respectively. Another two studies found improved survival with OR 1.2 (1.0-1.5) and 6.9 (1.48-32.5) in patients transported by PS-HEMS compared with GEMS. In three studies, PS-HEMS was associated with shorter time to hospital. Three studies reported quality of life and found no benefit of PS-HEMS.

Conclusion: In this systematic review the studies comparing PS-HEMS with GEMS were difficult to summarize because of heterogeneity. We found a possible survival benefit of PS-HEMS but were unable to conduct a meta-analysis. The overall quality of evidence was low.