Validation of Factors Associated with Difficult Emergency Transport in Tokyo Before and After COVID-19 Pandemic: A Retrospective Observational Study. - Osugi I; Usuda D; Inami T; Kato M; Nakajima E; Shimizu R; Komatsu T; Mizuno K; Takami H; Nomura T; Sugita M (Juntendo medical journal, 2026)