title: A practical approach to pediatric patients referred with an abnormal coagulation profile.
abstract: BACKGROUND
  Workup for prolonged prothrombin time (PT) and activated partial thromboplastin time (PTT) is a frequent referral to a Hematology and Coagulation Laboratory. Although the workup should be performed in a timely and cost-effective manner, the complete laboratory assessment of the coagulation state has not been standardized.
  
  
  OBJECTIVE
  To determine which clinical and laboratory data are most predictive of a coagulopathy and to formulate the most efficient strategy to reach a diagnosis in patients referred for abnormal coagulation profiles.
  
  
  METHODS
  Retrospective case review. Medical records of 251 patients referred for prolonged PT and/or PTT to our Hematology Service between June 1995 and December 2002 were reviewed.
  
  
  RESULTS
  The study included 135 males and 116 females with a mean age of 7.0 years. A personal history of bleeding was reported in 137 patients, and a family history of bleeding was reported in 116 patients. Fifty-one patients (20%) had a coagulopathy (ie, a bleeding risk). Factors predictive of a bleeding risk were a positive family history of bleeding (P < .001) and a positive personal history of bleeding (P = .001). Of 170 patients with findings of normal PT and PTT values on repeat testing, 14 were subsequently diagnosed with a coagulopathy. Two of these patients reported no positive personal or family history of bleeding.
  
  
  CONCLUSIONS
  Coagulopathy was identified in 20% of the children referred for abnormal PT and/or PTT. In the absence of a personal or family history of bleeding, a normal PT and/or PTT on repeat testing has a negative predictive value of more than 95%.
authors.affiliation: Department of Pediatrics, Cancer Center & Hematology Service, Texas Children's Hospital, Houston, TX 77030, USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Acosta
authors.forename: Rachel
authors.initials: R
authors.lastname: Edwards
authors.forename: Ian M
authors.initials: IM
authors.lastname: Jaffee
authors.forename: E Ian
authors.initials: EI
authors.lastname: Jaffe
authors.forename: Donald L
authors.initials: DL
authors.lastname: Yee
authors.forename: Donald H
authors.initials: DH
authors.lastname: Mahoney
authors.forename: Jun
authors.initials: J
authors.lastname: Teruya
mesh_terms: D001777:Blood Coagulation; D001778:Blood Coagulation Disorders / Q000097:blood / Q000175:diagnosis*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D010314:Partial Thromboplastin Time; D010372:Pediatrics / Q000379:methods*; D011237:Predictive Value of Tests; D011517:Prothrombin Time; D012017:Referral and Consultation; D012189:Retrospective Studies; D012307:Risk Factors