Does clinical probability estimation combined with D-dimer testing accurately exclude deep vein thrombosis?
In patients with a low clinical probability of DVT, a negative D-dimer test safely excludes the diagnosis without requiring an ultrasound.
Diagnostic accuracy for DVT improves when clinical probability is estimated before diagnostic tests. Patients with low clinical probability on the predictive rule have prevalence of DVT of less than 5%. In low-probability patients with negative D-dimer results, diagnosis of DVT can be excluded without ultrasound; in patients with high clinical suspicion for DVT, results should not affect clinical decisions.
Philip S. Wells (2006) studied this question.