BACKGROUND: Compression ultrasonography is the mainstay of diagnosis of @entity1150 ( @entity1150 ) of the legs. Compression ultrasonography can be extended to the entire deep venous system (whole-leg) or restricted to the proximal veins only (limited), and the two approaches are clinically equivalent. We aimed to assess the diagnostic value of an algorithm combining whole-leg and limited compression ultrasonography. METHODS: We did a prospective, multicentre, cohort study at eight centres in five countries. Consecutive outpatients aged 18 years or older with suspected @entity1150 underwent D-dimer measurement and pretest clinical probability assessment. @entity1150 was ruled out without further testing if pretest probability was unlikely and D-dimer was negative (group 1). @entity1 in whom either pretest probability was likely or who were positive for D-dimer underwent limited compression ultrasonography only (group 2). Finally, @entity1 in whom pretest probability was likely and who had a positive measurement for D-dimer underwent extended whole-leg compression ultrasonography (group 3). All @entity1 in whom @entity1150 was ruled out were followed up for 3 months. The primary outcome was the incidence of objectively recorded @entity1211 . The primary analysis included all @entity1 managed according to the study protocol. This study is registered with ClinicalTrials.gov, number NCT01412242. The final results are reported here. FINDINGS: Between March 1, 2011, and July 31, 2014, 1348 consecutive outpatients were referred for this study, of whom 1162 were eligible to participate. After pretest probability assessment and D-dimer testing, 351 were in group 1, 401 in group 2, and 410 in group 3. Limited compression ultrasonography was positive in 12 (3%) @entity1 in group 2 and extended whole-leg compression ultrasonography was positive in 200 (49%) @entity1 in group 3. 82 (39%) of all @entity1150 diagnosed at baseline were isolated distal thromboses. 26 protocol violations were reported. Thus, 351 @entity1 from group 1, 371 @entity1 in group 2, and 202 @entity1 in group 3 who had been excluded for @entity1150 by the algorithm were included in the primary analysis at 3 months. One, four, and three DVTs were reported, respectively. Thus, the 3-month incidence of @entity1211 in untreated @entity1 after a negative diagnostic strategy was 0  87% (95% CI 0  44-1  70). INTERPRETATION: An algorithm combining limited and whole-leg compression ultrasonography could be a reliable, safe, and convenient method for diagnostic management of outpatients with clinically suspected @entity1150 . FUNDING: None.

Analysis of an algorithm incorporating limited and whole-leg assessment of the deep venous system in symptomatic outpatients with suspected XXXX (PALLADIO): a prospective, multicentre, cohort study.

@entity1150 :: ('MESH:D020246', 'Disease') :: ['deep-vein thrombosis', 'DVT'] @entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity1211 :: ('MESH:D054556', 'Disease') :: ['venous thromboembolism']
@entity1150 :: (MESH:D020246,Disease) :: ['deep-vein thrombosis']
