Analysis of the Adequacy of Prehospital Emergency Medical Services Use of Patients Who Visited Emergency Departments in Korea from 2016 to 2018: Data from the National Emergency Department Information System

Figure 1

Flow chart describing case enrollment. Of 18,298,535 patients, 11,668,581 patients (63.77%) had appropriate usage and 6,629,954 (36.23%) had inappropriate usage. Around 2,408,845 (13.16%) belonged to the appropriate (ambulance used) group, 5,147,352 (28.13%) belonged to the underuse group, 9,259,706 (50.60%) belonged to the appropriate (no ambulance used) group, and 1,482,602 (8.10%) belonged to the overuse group. KTAS: Korean Triage and Acuity Scale.