title: Diagnosing deep vein thrombosis in the lower extremity: correlation of clinical and duplex scan findings.
abstract: OBJECTIVE
  To identify factors that predict a positive duplex scan examination result in patients with suspected deep vein thrombosis of the lower extremity.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Vascular laboratory in a university teaching hospital.
  
  
  METHODS
  The results of 345 lower extremity duplex venous scans performed between August 1994 and November 1998 were reviewed. All patients were in-patients referred from different specialties due to clinical suspicion of lower extremity deep vein thrombosis. Positive duplex scans were correlated with patients' demographic data (sex, age), medical history (history of malignancy, deep vein thrombosis, and pulmonary embolism) and clinical features (leg swelling, venous insufficiency, calf pain, and leg ulcer). Univariate analysis was performed using the Chi squared test.
  
  
  RESULTS
  A total of 345 scans were performed for 313 patients. The mean age was 55 years (range, 19-92 years). Sixty-three patients (49 male, 14 female) had a positive scan, giving a yield of 18.3%. Four factors had a significant association with a positive scan: male sex (P=0.0102), history of malignancy (P=0.0040), history of deep vein thrombosis (P=0.0001), and history of pulmonary embolism (P=0.0265).
  
  
  CONCLUSIONS
  Common presenting clinical features do not predict the result of ultrasonographic investigation for deep vein thrombosis. The chance of having a positive scan is significantly higher in male patients and those with a history of malignancy, deep vein thrombosis, or pulmonary embolism.
authors.affiliation: Department of Surgery, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong.
authors.forename: Y M
authors.initials: YM
authors.lastname: Lee
authors.forename: A C W
authors.initials: AC
authors.lastname: Ting
authors.forename: S W K
authors.initials: SW
authors.lastname: Cheng
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013924:Thrombophlebitis / Q000000981:diagnostic imaging*; D018616:Ultrasonography, Doppler, Duplex