From the Department of Obstetrics and Gynecology (K.K.), Nagano Prefectural Kiso Hospital, Kiso-gun; Department of Clinical Epidemiology and Health Economics (M.N., D.S., H.O., T.G., H.M., H.Y.), School of Public Health, The University of Tokyo; Emergency and Critical Care Center (M.N., R.H.K.), Tokyo Metropolitan Hiroo Hospital; Emergency Life-Saving Technique Academy of Tokyo (M.N.), Foundation for Ambulance Service Development, Tokyo; Data Science Center (Y.S.), Jichi Medical University, Tochigi; and Department of Health Policy and Informatics (K.F.), Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan.

Submitted: March 10, 2022, Revised: March 30, 2022, Accepted: April 4, 2022, Published online: April 21, 2022.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text, and links to the digital files are provided in the HTML text of this article on the journal’s Web site (www.jtrauma.com).

Address for reprints: Mikio Nakajima, MD, MPH, PhD, Emergency Life-Saving Technique Academy of Tokyo, Foundation for Ambulance Service Development, Tokyo, Japan, 4-5, Minami-Osawa, Hachioji-shi, Tokyo 192-0364, Japan; e-mail: [email protected]