[1] Univ Tsukuba, Fac Med, Dept Anesthesiol, Tennodai 1-1-1, Tsukuba, Ibaraki 3058575, Japan
[2] Natl Hosp Org Kasumigaura Med Ctr, Tsuchiura Ctr Med Educ & Training, Dept Anesthesiol, Tsuchiura, Ibaraki, Japan
[3] Tokyo Univ Pharm & Life Sci, Sch Pharm, Dept Drug Safety & Risk Management, Tokyo, Japan
[4] Natl Hosp Org Headquarters, Clin Res Ctr, Dept Clin Data Management & Res, Tokyo, Japan