Aya Sugiyama,1 Teruhisa Fujii,2,3 Yoshiko Okikawa,4 Fumie Sasaki,5 Masazumi Okajima,3,6 Hidekuni Hidaka,3,7 Koji Iwato,3,8 Kazuyoshi Sato,3,9 Akira Kokubunji,3,10 Noboru Takata,3,11 Masahiro Yamamoto,3,12 Junko Tanaka1,3 1Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; 2Division of Transfusion Medicine, Hiroshima University Hospital, Hiroshima, Japan; 3Joint Committee for Blood Transfusion Therapy in Hiroshima Prefecture, Hiroshima, Japan; 4Department of Oncology, Hiroshima City Hiroshima Citizens Hospital, Hiroshima, Japan; 5Division of Laboratory, Hiroshima City Hiroshima Citizens Hospital, Hiroshima, Japan; 6Department of Surgery, Hiroshima City Hiroshima Citizens Hospital, Hiroshima, Japan; 7Division of Surgical Services, Fukuyama City Hospital, Hiroshima, Japan; 8Department of Hematology, Hiroshima Red Cross Hospital & Atomic-Bomb Survivors Hospital, Hiroshima, Japan; 9Division of Laboratory, Shobara Red Cross Hospital, Shobara, Japan; 10Department of Medical Science and Technology, Faculty of Health Sciences, Hiroshima International University, Hiroshima, Japan; 11Oda Internal Medical Clinic, Hiroshima, Japan; 12Hiroshima Red Cross Blood Centre, Hiroshima, JapanCorrespondence: Teruhisa FujiiDivision of Transfusion Medicine, Hiroshima University Hospital, 1-2-3, Kasumi, Minami-ward, Hiroshima, 734-8551, JapanTel +81-82-257-5581Email terchan@hiroshima-u.ac.jpPurpose: Given the chronic shortage of blood for transfusion in Japan, promotion of appropriate use of fresh frozen plasma (FFP) urgently needs to be addressed by the national blood project in Japan. Whether FFP transfusions are administered appropriately in Japan is currently unclear. In this study, we aimed to investigate the outcomes of patients who undergo FFP transfusion and the appropriateness of use of FFP.Patients and Methods: This multicentre, prospective, observational cohort study was conducted from September 2017 to April 2019 at the 15 medical institutions in Hiroshima Prefecture that are the top providers of FFP. All patients who underwent FFP transfusion during the study period were included, relevant data being extracted from the medical records. The indications for FFP transfusion were classified in accordance with the Guidelines of the Ministry of Health, Labour and Welfare of Japan. Factors associated with patient outcomes at day 28 after FFP transfusion were subjected to multivariable logistic regression analysis.Results: In total, data of 1299 patients were eligible for analysis. At least 63.8% of indications for FFP were in accordance with the guideline for FFP transfusions. The mortality rate at day 28 after FFP transfusion was 16.2%. Older age (65â 74 years: adjusted odds ratio [AOR]=4.3, ⥠75 years: AOR=4.1), non-perioperative use (AOR=4.5), coagulopathy associated with liver damage (AOR=2.7), large volume of FFP transfused (AOR=2.5), and lack of improvement in blood coagulation following FFP transfusion were independently and significantly associated with death within 28 days after FFP transfusion.Conclusion: Our findings do not support the simple conclusion that FFP transfusions contribute to prognosis. However, given that coagulopathy in patients with end-stage liver disease is infrequently improved by FFP transfusion, âinappropriateâ use of FFP should be avoided. It is important to promote appropriate use of FFP so as not to waste blood resources.Keywords: prognosis, coagulopathy, inappropriate use, compliance with guideline