Deep vein thrombosis: a clinical prediction guide and a d-dimer can help rule out a DVT

Clinical bottom line (level 1b)

  1. One in five patients suspected of having a DVT had one.
  2. A negative d-dimer made a DVT less likely (LR - 0.23) .
  3. A low-risk clinical score and a normal d-dimer make a DVT unlikely (2%) (LR - 0.079) .
Aschwanden et al: Journal of Vascular Surgery 1999; 30 : 929-935
Expires November 2003

The study

Setting: university hospital, Switzerland

343 patients (aged 17 to 94; median 61, 61% female) with a suspected DVT referred for imaging. Patients were ranked using a validated clinical prediction rule for risk of DVT (low v. moderate or high)

Excluded if
  • incomplete information available


    Independent blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
    Reference standard:
    • ultrasound scanning
    Diagnostic test: whole blood agglutination d-dimer (SimpliRED)

    The evidence

    pre-test probability of DVT: 21%, (95% CI: 17% to 25%)

    diagnostic test DVT no DVT LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    d-dimer 72 135 2.0
    (1.7 to 2.4)     		35% 0.23
    (0.13 to 0.41)     		6%
    any result other than low risk and normal d-dimer 80 171 1.8
    (1.6 to 2.0)     		32% 0.079
    (0.026 to 0.24)     		2%
    total 83 315

    Comments

    1. Results were calculated based on number of legs studied (398)

    Citation

    1. Aschwanden M, Labs KH, Jeanneret C, et al: the value of rapid D-dimer testing combined with structured clinical evaluation for the diagnosis of deep vein thrombosis. Journal of Vascular Surgery 1999; 30 : 929-935
    Search Terms: from ACP Journal Club other articles noted
    Contributor: Chris Ball, November 2001
    Reviewer:

    Clinical Question.
    Patient suspected DVT
    Intervention or Exposure d-dimer and clinical prediction guide
    Outcome deep vein thrombosis