Table 1.

Total number of patients and observations for the five hospitals.

	CAUH ${}^{\mathit{a}}$	SNUH ${}^{\mathit{b}}$	NTIRH ${}^{\mathit{c}}$	CUYMH ${}^{\mathit{d}}$	AMC e
The number of patients	29	7	132	173	42
The number of observations	85	34	691	571	242

^a Chung-Ang University Hospital, ^b Seoul National University Hospital, ^c National Traffic Injury Rehabilitation Hospital, ^d The Catholic University of Korea Yeouido St. Mary’s Hospital, and e Asan Medical Center.