title: The performance of age-adjusted D-dimer cut-off in Chinese outpatients with suspected venous thromboembolism.
abstract: BACKGROUND
  D-dimer testing has been widely used in the exclusion of venous thromboembolism (VTE), but its clinical usefulness is limited in older patients because of a lower specificity.
  
  
  OBJECTIVE
  To evaluate the diagnostic performance of STA-Liatest D-dimer assay and validate the age-adjusted cut-off value in Chinese outpatients with suspected VTE in a prospective non-interventional study.
  
  
  METHODS
  Symptomatic patients suspected of having deep venous thrombosis or pulmonary embolism were recruited from 2 participating centers. STA-Liatest D-dimer assay, clinical pretest probability assessment and diagnostic imaging test including complete compression ultrasonography or computed tomography pulmonary angiography were performed among all participants. The performance of D-dimer test was assessed with an age-adjusted D-dimer cut-off (age×0.01μg/ml in patients aged>50years) and with conventional cut-off (0.5μg/ml at all ages).
  
  
  RESULTS
  A total of 594 eligible outpatients were included in this study and VTE was diagnosed in 195 (32.8%) patients. In those patients with a low or moderate pretest probability (n=373), the increase in the proportion of patients with a D-dimer below the age-adjusted cut-off value compared with the conventional cut-off value was 5.9% (95% confidence interval; 3.8%-8.7%). The sensitivity, specificity and negative predictive value of STA-Liatest D-dimer test were 95.0% (83.5% - 98.6%), 84.1%(79.8%-87.6%) and 99.3%(97.5% - 99.8%), respectively, using the age-adapted diagnostic strategy.
  
  
  CONCLUSIONS
  The application of age-adjusted cut-off of D-dimer test combined with clinical probability greatly increases the proportion of Chinese older outpatients in whom VTE can be safely excluded.
authors.affiliation: Department of Laboratory Medicine, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Chengwu
authors.initials: C
authors.lastname: Han
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Cardiology, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Wenli
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Cardiology, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Department of Vascular Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Department of Laboratory Medicine, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Yu
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China. Electronic address: tienanzhu@gmail.com.
authors.forename: Tienan
authors.initials: T
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D011655:Pulmonary Embolism / Q000175:diagnosis*; D054556:Venous Thromboembolism / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: D-dimer; Deep vein thrombosis; Diagnosis; Pulmonary embolism; Venous thromboembolism