Abstract
Essentials The aim of deep vein thrombosis (DVT) diagnostic work-up is to maximize both safety and efficiency. We explored whether D-dimer is safe and efficient as a stand-alone test to exclude DVT. Our findings suggest it is a safe, efficient and simplified diagnostic strategy. The safety of age-adjusted D-dimer as a stand-alone test requires further investigation. SUMMARY: Background Several strategies for safely excluding deep vein thrombosis (DVT) while limiting the number of imaging tests have been explored. Objectives To determine whether D-dimer testing could safely and efficiently exclude DVT as a stand-alone test, and evaluate its performance as compared with strategies that incorporate the Wells score and age-adjusted D-dimer. Patients/Methods We included consecutive outpatients referred with suspected DVT to the Emergency Department at Østfold Hospital, Norway. STA-Liatest D-Di PLUS D-dimer was analyzed for all patients. Patients with a D-dimer level of ≥0.5μgmL-1 were referred for compression ultrasonography (CUS). In patients with a D-dimer level of <0.5μgmL-1 , no further testing was performed and anticoagulation was withheld. Patients were followed for 3months for venous thromboembolism (VTE). Results Of the 913 included patients, 298 (33%) had a negative D-dimer result. One hundred and seventy-three patients (18.9%) were diagnosed with DVT at baseline. One of 298 patients had DVT despite having a negative D-dimer result, resulting in a failure rate of 0.3% (95% confidence interval [CI]0.1-1.9%). Adding the modified Wells score would have yielded a failure rate of 0.0% (95%CI0.0-1.8%) while necessitating 87 more CUS examinations. Age-adjusted D-dimer as a stand-alone test would have necessitated 80 fewer CUS examinations than fixed D-dimer as a stand-alone test, at the cost of a failure rate of 1.6% (95%CI0.7-3.4%). Conclusions This outcome study shows that a negative high-sensitivity D-dimer result safely excludes DVT in an outpatient population, and necessitates fewer CUS than if used in combination with Wells score. The safety of stand-alone age-adjusted D-dimer needs further assessment in prospective outcome studies.
Highlights
Clinical pretest probability evaluation and D-dimer testing have long been the standard initial step of deep vein thrombosis (DVT) diagnostic work-up [1]
One of 298 patients had DVT despite a negative D-dimer, resulting in a failure rate of 0.3%
Adding the modified Wells score would have yielded a failure rate of 0.0% while necessitating 87 more compression ultrasonography (CUS)
Summary
Clinical pretest probability evaluation and D-dimer testing have long been the standard initial step of deep vein thrombosis (DVT) diagnostic work-up [1]. Assessing pretest probability supported by clinical prediction rules is recommended to guide further testing and to minimize the risk of false negative results among patients with high pretest probability of DVT. In a later modified version of Wells score, another clinical item was added, yielding one point for previously documented DVT [4] and dichotomizing groups into ‘DVT unlikely’ (
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
