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The Article in Brief
Comparing the Diagnostic Performance of 2 Clinical Decision Rules to Rule Out Deep Vein Thrombosis in Primary Care Patients
Eit Frits van der Velde , and colleagues
Background The Wells clinical prediction rule for assessment of patients with suspected deep vein thrombosis is widely used, especially in secondary care settings. Recently, a new clinical decision rule for primary care patients has been proposed. This study compares the two rules on their ability to safely rule out a diagnosis of deep vein thrombosis among primary care patients and reduce the number of referrals for negative findings on leg ultrasound tests.
What This Study Found Both clinical decision rules, when used in combination with a point-of-care D-dimer blood test, are effective and can spare almost half of patients an unnecessary referral for ultrasound. This study of 1,002 patients with possible deep vein thrombosis found a venous thromboembolic event occurred during follow-up in 7 patients with a low score and a negative blood test, both with the Wells rule and primary care rule. Direct medical costs per patient were about the same using both rules. Using the Wells rule, 447 patients (45 percent) would not need referral for further testing compared with 495 (49 percent) when using the primary care rule.
Implications
- The authors suggest that the primary care rule, which prevents slightly more unnecessary ultrasound procedures than the Wells rule, is somewhat more convenient for both patients and physicians.