A Red Blood Cell Agglutination D-dimer Test to Exclude Deep Venous Thrombosis in Pregnancy: Chan W-S, Chunilal S, Lee A, et al. Ann Intern Med 2007;147:165–70

Abstract

This prospective cohort study was designed to determine the sensitivity, specificity, negative predictive value, and false-positive rates of the SimpliRED (latex agglutination) D-dimer assay for the diagnosis of deep venous thrombosis (DVT) in pregnant women. The authors enrolled 149 consecutive pregnant women with suspected DVT over a 5-year period. All patients had the SimpliRED D-dimer assay performed at presentation along with compression ultrasonography (US). All patients also had a minimum of 3 months of clinical follow-up. Twelve cases of DVT were diagnosed by US at initial presentation, and 1 patient developed pulmonary embolism within the follow-up period, yielding an overall prevalence of venous thromboembolic disease of 8.7% (95% confidence interval [CI] 5.2–14.4%). The sensitivity of the D-dimer assay was 100% (95% CI 77–100%) and the specificity was 60% (95% CI 52–68%). The negative predictive value of the assay was 100% (95% CI 95–100%). False-positive rates were 0% (95% CI 0–60%), 24% (95% CI 14–37%) and 51% (95% CI 40–61%) in the first, second, and third trimesters, respectively. The authors conclude that the SimpliRED D-dimer assay may be clinically useful in pregnancy, and a negative result effectively excludes DVT.