Six prospective studies were included (n=936).
Four studies reported adequate blinding. Methodological limitations included the small number of EP sonographers and their high level of experience, insufficient information about patients and the anatomical location of the DVT and lack of discussion about missed calf vein thrombosis.
Pooled sensitivity was 0.95 (95% CI: 0.87, 0.99) and pooled specificity was 0.96 (95% CI: 0.87, 0.99). No evidence of a significant threshold effect was found. There was substantial heterogeneity (I2 77%). Sensitivity values were 1.0 to 0.98. Most specificity values ranged from 0.92 to 0.99; in one study specificity was 0.76.