Natural Experiment Outcomes Studies in Rotor Wing Air Medical Transport: Systematic Review and Meta-Analysis of Before-and-After and Helicopter-Unavailable Publications From 1970 to 2022
airmedicaljournal.com reports: Helicopter emergency medical services (HEMS) is widely used for prehospital and interfacility transport, but there is a paucity of HEMS outcomes data from studies using randomized controlled trial designs.