title: "Blue letter effects": Changes in physicians' attitudes toward dabigatran after a safety advisory in a specialized hospital for cardiovascular care in Japan.
abstract: BACKGROUND
  A blue letter (safety advisory) for dabigatran was issued by the Japanese Ministry of Health, Labour and Welfare in August 2011. Changes in physicians' attitudes toward dabigatran use before and after the blue letter have not been previously reported.
  
  
  RESULTS
  Between March 2011 and July 2012, dabigatran was prescribed to 404 Japanese patients with nonvalvular atrial fibrillation at The Cardiovascular Institute (Tokyo, Japan). Patients were divided into three groups according to the first prescription date: phase I (before the blue letter, n=135); phase II (after the blue letter and before permission for longer-term prescriptions, n=112); and phase III (after permission for longer-term prescriptions, n=157). In phase II, dabigatran use tended to be avoided for patients with older age, renal dysfunction, receiving antiplatelet medication, or p-glycoprotein inhibitors. Measurement of activated partial thromboplastin time significantly increased from phase I to III. In phase III, the tendencies seen in phase II were reversed: dabigatran use in patients with older age and renal dysfunction tended to increase, but decreased or remained the same in patients receiving antiplatelet medications or p-glycoprotein inhibitors.
  
  
  CONCLUSIONS
  We described the changes in the attitudes of attending physicians toward dabigatran prescription after the blue letter in a specialized hospital for cardiovascular care in Japan, which, we believe, involve useful information for safe use of dabigatran in a real-world clinical setting. However, a true impact or effect of the blue letter should be ascertained in a nationwide, multicenter study.
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan. Electronic address: sinsuz-tky@umin.ac.jp.
authors.forename: Shinya
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Sagara
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Otsuka
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kano
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Matsuno
authors.affiliation: Department of Cardiovascular Surgery, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takai
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Tokuhisa
authors.initials: T
authors.lastname: Uejima
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Oikawa
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Koike
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Nagashima
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Kirigaya
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Yajima
authors.affiliation: Department of Cardiovascular Surgery, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanabe
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sawada
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Tadanori
authors.initials: T
authors.lastname: Aizawa
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamashita
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000188:drug therapy*; D001291:Attitude of Health Personnel; D001562:Benzimidazoles / Q000008:administration & dosage / Q000009:adverse effects; D000075202:Contraindications; D000069604:Dabigatran; D005260:Female; D006077:Government Agencies; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D010820:Physicians / Q000523:psychology*; D012449:Safety; D015091:beta-Alanine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D001562:Benzimidazoles; D015091:beta-Alanine; D000069604:Dabigatran
keywords: Atrial fibrillation; Renal function; Risk factors