title: Risk factor assessment in the management of patients with suspected deep venous thrombosis.
abstract: BACKGROUND
  To evaluate the prevalence of thrombosis risk factors in a group of patients undergoing venous duplex scanning (VDS) and to design a risk factor stratification model with the ability to improve the diagnostic yield of VDS.
  
  
  METHODS
  Risk factor assessment and VDS were performed on 1,000 patients with clinically suspected lower extremity deep vein thrombosis (DVT) and patients were divided into two groups based upon the outcome of their scan: those with and those without confirmed DVT. Univariate and multivariate logistic regression analyses were performed in order to determine the significance of each risk factor in relation to having a confirmed DVT.
  
  
  RESULTS
  There were 181 patients (18.1%) with confirmed DVT. A prior history of DVT/pulmonary embolism, malignancy, prior immobilization, and age over 70 were the most important risk factors associated with having a DVT confirmed on VDS. A novel risk factor stratification model was created utilizing the odds ratios of those factors found to be significant and the prevalence of DVT was found to be 92.4% in the high risk category, 11.5% in the moderate risk category, and 3.2% in the low risk category using this model.
  
  
  CONCLUSIONS
  Venous duplex scanning is established as the screening test of choice when one suspects the diagnosis of DVT despite the significant cost of performing and interpreting the test. We suggest that a better clinical model utilizing risk factor assessment may be the key to increasing the yield rate and cost-effectiveness of VDS by excluding low-risk patients from undergoing unnecessary testing.
authors.affiliation: Department of Surgery, Evanston Northwestern Healthcare, IL 60201, USA.
authors.forename: G D
authors.initials: GD
authors.lastname: Motykie
authors.forename: J A
authors.initials: JA
authors.lastname: Caprini
authors.forename: J I
authors.initials: JI
authors.lastname: Arcelus
authors.forename: L P
authors.initials: LP
authors.lastname: Zebala
authors.forename: C E
authors.initials: CE
authors.lastname: Lee
authors.forename: N M
authors.initials: NM
authors.lastname: Finke
authors.forename: A
authors.initials: A
authors.lastname: Tamhane
authors.forename: J J
authors.initials: JJ
authors.lastname: Reyna
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D018616:Ultrasonography, Doppler, Duplex; D020246:Venous Thrombosis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology