title: Evaluation of Wells score and repeated D-dimer in diagnosing venous thromboembolism.
abstract: BACKGROUND
  Patients presenting with symptoms suggestive of venous thromboembolism (VTE), i.e., deep vein thrombosis (DVT) and pulmonary embolism (PE), are common at the emergency departments. However, of those, only 15-25% actually have the disease. The aims of this study were to determine (1) if low pre-test probability (PTP) using the Wells score, together with a normal D-dimer, safely excludes VTE in outpatients and (2) if a follow-up D-dimer adds extra information.
  
  
  METHODS
  Patients (n=151, 68% women) with suspected VTE, a PTP below 1.5, and a D-dimer test (TinaQuant) below 0.5 mg/L were included in the study and underwent no further diagnostic investigations. Patients (n=177, 54% women) with D-dimer levels of 0.5 mg/L or higher or a PTP of 1.5 or higher were excluded. A follow-up D-dimer test was conducted 3-7 days after the initial hospital visit and further diagnostic investigations were made if test results were abnormal. Patients were studied for 3 months.
  
  
  RESULTS
  A follow-up D-dimer test was conducted in 101/151 cases (67%), 13/101 of which revealed elevated D-dimer levels. None of these 13 patients had persistent symptoms or was diagnosed with VTE. All 151 patients were contacted after 3 months; none of them had clinical signs of VTE. Of the 177 patients excluded, 45 (25%) were diagnosed with VTE. Of the 176/328 (151+177) patients with normal D-dimer levels, only 1 had VTE (<0.01%).
  
  
  CONCLUSIONS
  A normal PTP using the Wells score and a normal D-dimer safely excludes VTE at the emergency department. A follow-up D-dimer test adds no further information.
authors.affiliation: Dept of Internal Medicine, Karolinska Institutet, Södersjukhuset, Stockholm, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Ljungqvist
authors.forename: Mårten
authors.initials: M
authors.lastname: Söderberg
authors.forename: Per
authors.initials: P
authors.lastname: Moritz
authors.forename: Anders
authors.initials: A
authors.lastname: Ahlgren
authors.forename: Gerd
authors.initials: G
authors.lastname: Lärfars
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000175:diagnosis*; D054556:Venous Thromboembolism / Q000175:diagnosis*; D020246:Venous Thrombosis / Q000175:diagnosis*
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D