Rational diagnosis of deep vein thrombosis (RADIA DVT) in symptomatic outpatients with suspected DVT: simplification and improvement of decision rule analysis for the exclusion and diagnosis of DVT by the combined use of a simple clinical model, a rapid sensitive D-dimer test and compression ultrasonography (CUS).

The diagnosis of deep vein thrombosis (DVT) in outpatients is difficult to establish. The classical clinical signs of DVT are unspecific and found in several other conditions besides DVT. Therefore, these patients are subjected to elaborate, expensive invasive or noninvasive procedures that actually confirm DVT in only 20-30% of patients in this setting. A prospective management decision study, based on a pretest clinical probability (PCP) estimation, compression ultrasonography (CUS), and a rapid enzyme-linked immunoadsorbent assay (ELISA) D-dimer test, is proposed. The PCP model of Wells allows for reasonably accurate classification of patients into low, moderate and high probability for suffering DVT. Combined with CUS, high predictability is achieved. The D-dimer assays presently available can be rapidly performed and are accurate to a high degree, especially in ruling out DVT. It is proposed to establish a "Rational Diagnosis of Deep Vein Thrombosis (RADIA DVT)" model to be tested in a large number of patients with suspected DVT. This model would be less expensive to perform and likely yield a highly accurate diagnosis on the basis of which anticoagulant therapy could be initiated or withheld.