Guideline No.	GRADE of recommendation	Level of evidence
2.1	1	A
We recommend that in patients with chronic venous disease, a complete history and detailed physical examination are complemented by duplex scanning of the deep and superficial veins. The test is safe, noninvasive, cost-effective, and reliable.
Guideline No.	GRADE of recommendation	Level of evidence
2.2	1	A
We recommend that the four components of a complete duplex scanning examination for chronic venous disease should be visualization, compressibility, venous flow, including measurement of duration of reflux, and augmentation.
Guideline No.	GRADE of recommendation	Level of evidence
2.3	1	A
We recommend that reflux to confirm valvular incompetence in the upright position of the patients be elicited in one of two ways: either with increased intraabdominal pressure using a Valsalva maneuver to assess the common femoral vein and the saphenofemoral junction, or for the more distal veins, use of manual or cuff compression and release of the limb distal to the point of examination.
Guideline No.	GRADE of recommendation	Level of evidence
2.4	1	B
We recommend a cutoff value of 1 second for abnormally reversed flow (reflux) in the femoral and popliteal veins and of 500 ms for the great saphenous vein, the small saphenous vein, the tibial, deep femoral, and the perforating veins.
Guideline No.	GRADE of recommendation	Level of evidence
2.5	1	B
We recommend that in patients with chronic venous insufficiency, duplex scanning of the perforating veins is performed selectively. We recommend that the definition of “pathologic” perforating veins includes those with an outward flow of duration of ≥500 ms, with a diameter of ≥3.5 mm and a location beneath healed or open venous ulcers (CEAP class C5-C6).