title: The value of helicopter service.
mesh_terms: D000401:Aircraft; D000552:Ambulances; D004636:Emergency Service, Hospital; D005069:Evaluation Studies as Topic; D006301:Health Services Needs and Demand; D006776:Hospitals, Pediatric; D009864:Ontario; D012040:Regional Health Planning; D014187:Transportation of Patients / Q000379:methods; D014505:Urban Population