title: Is the HAS-BLED score useful in predicting post-extraction bleeding in patients taking warfarin? A retrospective cohort study.
abstract: OBJECTIVE
  Unexpected post-extraction bleeding is often experienced in clinical practice. Therefore, determining the risk of post-extraction bleeding in patients receiving anticoagulant therapy prior to surgery is beneficial. This study aimed to verify whether the HAS-BLED score was useful in predicting post-extraction bleeding in patients taking warfarin.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Department of Oral and Maxillofacial Surgery, Tokyo Women's Medical University.
  
  
  METHODS
  Participants included 258 sequential cases (462 teeth) who had undergone tooth extraction between 1 January 2010 and 31 December 2012 while continuing warfarin therapy.
  
  
  METHODS
  Post-extraction risk factors for bleeding. The following data were collected as the predicting variables for multivariate logistic analysis: the HAS-BLED score, extraction site, tooth type, stability of teeth, extraction procedure, prothrombin time-international normalised ratio value, platelet count and the use of concomitant antiplatelet agents.
  
  
  RESULTS
  Post-extraction bleeding was noted in 21 (8.1%) of the 258 cases. Haemostasis was achieved with localised haemostatic procedures in all the cases of post-extraction bleeding. The HAS-BLED score was found to be insufficient in predicting post-extraction bleeding (area under the curve=0.548, p=0.867, multivariate analysis). The risk of post-extraction bleeding was approximately three times greater in patients taking concomitant oral antiplatelet agents (risk ratio=2.881, p=0.035, multivariate analysis).
  
  
  CONCLUSIONS
  The HAS-BLED score alone could not predict post-extraction bleeding. The concomitant use of oral antiplatelet agents was a risk factor for post-extraction bleeding. No episodes of post-extraction bleeding required more than local measures for haemostasis. However, because this was a retrospective study conducted at a single institution, large-scale prospective cohort studies, which include cases of outpatient tooth extraction, will be necessary in the future.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kataoka
authors.affiliation: Department of Hygiene, School of Medicine, Kitasato University, Kanagawwa, Japan.
authors.forename: Keika
authors.initials: K
authors.lastname: Hoshi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Ando
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects*; D001281:Atrial Fibrillation / Q000628:therapy; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D019106:Postoperative Hemorrhage / Q000453:epidemiology / Q000209:etiology*; D011517:Prothrombin Time; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D014041:Tokyo; D014081:Tooth Extraction / Q000009:adverse effects*; D014859:Warfarin / Q000009:adverse effects*
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: HAS-BLED score; concomitant antiplatelet agents; post-extraction bleeding; warfarin