title: Diagnosis of lower limb deep venous thrombosis in emergency department patients: performance of Hamilton and modified Wells scores.
abstract: OBJECTIVE
  We validate and compare the Hamilton score for assessment of lower limb deep venous thrombosis with the modified Wells score.
  
  
  METHODS
  Consecutive patients presenting to the emergency department of a tertiary center for suspected lower limb deep venous thrombosis were prospectively recruited. Hamilton score and modified Wells score calculations, D-dimer, and complete (calf veins included), single lower limb ultrasonographic examination were performed for all patients. All patients with a negative ultrasonographic examination result for deep venous thrombosis were followed up for 3 months.
  
  
  RESULTS
  The study population consisted of 116 men and 193 women, with an average age of 55.6 years (SD 20.1). A total of 67 (21.7%) patients were diagnosed with deep venous thrombosis. Forty (59.7%) of these patients had isolated calf deep venous thrombosis, and the other 27 (40.3%) patients had proximal deep venous thrombosis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) for an unlikely Hamilton score (score < or = 2) and D-dimer were 99% (95% confidence interval [CI] 92% to 99.96%), 42 % (95% CI 36% to 49%), 32% (95% CI 26% to 39%), 99% (95% CI 95% to 99.98%), 1.7 (95% CI 1.52% to 1.9%), and 0.04 (95% CI 0.01 to 0.25), respectively. The sensitivity, specificity, PPV, NPV, LR+ and LR- for an unlikely modified Wells score (score < or = 1) and D-dimer were 99% (95% CI 92% to 99.96%), 33 % (95% CI 27% to 39%), 29% (95% CI 23% to 35%), 99% (95% CI 93% to 99.97%), 1.47 (95% CI 1.34 to 1.62), and 0.05 (95% CI 0.01 to 0.32), respectively.
  
  
  CONCLUSIONS
  An unlikely probability of Hamilton score and a negative D-dimer may effectively exclude a lower limb deep venous thrombosis. Hamilton and modified Wells scores have similar performance characteristics.
authors.affiliation: Department of Radiology, Waikato Hospital, Hamilton, New Zealand. rathan67@hotmail.com
authors.forename: Rathan M
authors.initials: RM
authors.lastname: Subramaniam
authors.forename: Brad
authors.initials: B
authors.lastname: Snyder
authors.forename: Rebekah
authors.initials: R
authors.lastname: Heath
authors.forename: Fiona
authors.initials: F
authors.lastname: Tawse
authors.forename: Jamie
authors.initials: J
authors.lastname: Sleigh
mesh_terms: D003625:Data Collection; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D012372:ROC Curve; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D