Selective D-dimer testing strategy seems safe, effective

(HealthDay)—For patients with suspected deep venous thrombosis (DVT), selective D-dimer testing is a safe and a more efficient testing strategy than universal testing, according to a study published in the Jan. 15 issue of the Annals of Internal Medicine.

Lori-Ann Linkins, M.D., from McMaster University in Hamilton, Canada, and colleagues randomized consecutive symptomatic patients with a first episode of suspected DVT to receive either selective testing (860 patients) or uniform testing (863 patients). Selective testing was defined as D-dimer testing in outpatients with low or moderate clinical pretest probability (C-PTP) (DVT excluded at D-dimer levels <1.0 µg/mL [low C-PTP] or <0.5 µg/mL [moderate C-PTP]) and venous ultrasonography without D-dimer testing in inpatients and outpatients with high C-PTP, while uniform testing was defined as D-dimer testing for all participants (with DVT excluded at D-dimer levels <0.5 µg/mL).

The researchers found that in both groups the incidence of symptomatic venous thromboembolism among patients not diagnosed with DVT during initial testing was 0.5 percent at three months. There was a 21.8 percent reduction in the proportion of patients who required D-dimer testing with the use of selective testing. With use of selective testing, the proportion of patients who required ultrasonography was reduced by 7.6 percent overall and by 21.0 percent for outpatients with low C-PTP.

"A selective D-dimer testing strategy seems as safe as and more efficient than having everyone undergo D-dimer testing when diagnosing a first episode of suspected DVT," the authors write.

Several authors disclosed financial ties to the pharmaceutical industry.