Table 2.

Study characteristics

Study characteristics (N = 47)	Category	Number of studies	%
Consecutive patients	Yes	37	79%
	NS*	10	21%
Work up Bias	No	39	83%
	Yes	6	13%
	NS	2	4%
Blind assessment	No	10	21%
	Yes	35	74%
	NS	2	4%
Settings	Orthopedic surgery	41	87%
	Abdominal surgery	2	4%
	Neurosurgery	2	4%
	Other surgery	1	2%
	Internal medicine	1	2%
Threshold Ultrasound	Compressibility and other	24	51%
	Compressibility	16	34%
	NS	7	15%
Examined Veins	Proximal and distal	28	60%
	Proximal only	18	38%
	NS	1	2%

^*Not Specified.