Table 1.

Baseline characteristics

Characteristic	Clinical Group (n = 106)	Ultrasound Group (n = 112)	P
Age			0.760
median [range]	67 [20 to 89]	69 [26 to 88]
25th percentile	55	60
75th percentile	76	75
Gender			0.496
male	70 (66.0%)	69 (61.6%)
female	36 (34%)	43 (38.4%)
Ethnicity			0.477
Caucasian	71 (67%)	80 (71.4%)
Indo-Asian	21 (19.8%)	25 (22.3%)
African	11 (10.4%)	4 (3.6%)
other	3 (2.8%)	3 (2.7%)
Body mass indexa	26.9 ± 6.2	27.1 ± 6.31	0.471
Hypertension	79 (75.2%)	87 (78.4%)	0.584
Diabetes	36 (34.3%)	48 (43.2%)	0.177
Cardiac diseaseb	38 (36.2%)	33 (29.7%)	0.312
Vascular diseasec	23 (21.9%)	16 (14.4%)	0.153
Antiplatelet agentd	55 (52.9%)	47 (42.3%)	0.122
Hemodialysis			0.955
not on hemodialysise	82 (77.4%)	87 (77.7%)
on hemodialysis	24 (22.6%)	25 (22.3%)
Difficult accessf	12 (11.3%)	12 (10.7%)	0.886
Surgical experience			0.549
surgical consultant alone	39 (39.8%)	47 (46.5%)
surgical consultant + trainee	41 (41.8%)	35 (34.7%)
surgical trainees alone	18 (18.4%)	19 (18.8%)

^aBody mass index data only available for approximately 62% of patients (clinical 57%, ultrasound 67%).

^bCardiac disease was defined by a clinical history of previous angina, acute coronary syndrome, coronary artery bypass graft, or cardiac transplant.

^cVascular disease was defined by a clinical history of claudication, critical leg ischemia, and endovascular or surgical intervention for peripheral arterial disease.

^dAntiplatelet agent = aspirin or clopidogrel or both.

^eNot on hemodialysis included patients with advanced chronic kidney disease (majority), failing peritoneal dialysis or renal transplant with plan to transfer to hemodialysis, and patients having started hemodialysis for less than 90 days.

^fDifficult access was defined as patients in whom no suitable site for AVF formation could be identified by clinical examination alone.