Validation of the Oudega diagnostic decision rule for diagnosing deep vein thrombosis in frail older out-of-hospital patients

Fam Pract. 2015 Feb;32(1):120-5. doi: 10.1093/fampra/cmu068. Epub 2014 Oct 27.


Objective: We aimed to validate the Oudega diagnostic decision rule-which was developed and validated among younger aged primary care patients-to rule-out deep vein thrombosis (DVT) in frail older outpatients.

Methods: In older patients (>60 years, either community dwelling or residing in nursing homes) with clinically suspected DVT, physicians recorded the score on the Oudega rule and d-dimer test. DVT was confirmed with a composite reference standard including ultrasonography examination and 3-month follow-up. The proportion of patients with a very low probability of DVT according to the Oudega rule (efficiency), and the proportion of patients with symptomatic venous thromboembolism during 3 months follow-up within this 'very low risk' group (failure rate) was calculated.

Results: DVT occurred in 164 (47%) of the 348 study participants (mean age 81 years, 85% residing in nursing homes). The probability of DVT was very low in 69 patients (Oudega score ≤3 points plus a normal d-dimer test; efficiency 20%) of whom four had non-fatal DVT (failure rate 5.8%; 2.3-14%). With a simple revised version of the Oudega rule for older suspected patients, 43 patients had a low risk of DVT (12% of the total population) of whom only one had DVT (failure rate 2.3%; 0.4-12%).

Conclusions: In older suspected patients, application of the original Oudega rule to exclude DVT resulted in a higher failure rate as compared to previous studies. A revised and simplified Oudega strategy specifically developed for elderly suspected patients resulted in a lower failure rate though at the expense of a lower efficiency.

Keywords: Clinical prediction rule; d-dimer; deep vein thrombosis; diagnosis; elderly; venous thromboembolism..

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Decision Support Techniques*
  • Female
  • Follow-Up Studies
  • Frail Elderly*
  • Homes for the Aged
  • Humans
  • Independent Living
  • Male
  • Nursing Homes
  • Prospective Studies
  • Reproducibility of Results
  • Venous Thrombosis / diagnosis*