Table 2

 Perioperative characteristics of entire cohort. Values are numbers (percentages) unless stated otherwise

Echocardiogram (n=40 084)No echocardiogram (n=224 739)Absolute standardised difference (%)
Hospital type
Teaching hospital12 943 (32.3)74 131 (33.0)1.5
Procedure quarter*:
 First (lowest)8458 (21.1)57 389 (25.5)10.4
 Second10 207 (25.5)53 198 (23.7)4.2
 Third10 692 (26.7)55 996 (24.9)4.1
 Fourth (highest)10 727 (26.8)58 156 (25.9)2.0
Procedure
Abdominal aortic aneurysm repair4288 (10.7)6115 (2.7)32.4
Carotid endarterectomy3172 (7.9)5710 (2.5)24.5
Peripheral vascular bypass2684 (6.7)7802 (3.5)14.6
Total hip replacement7143 (17.8)52 667 (23.4)13.9
Total knee replacement11 277 (28.1)79 998 (35.6)16.2
Large bowel surgery5807 (14.5)47 153 (21.0)17.1
Liver resection216 (0.5)1539 (0.7)2.6
Whipple procedure171 (0.4)1358 (0.6)2.8
Pneumonectomy or lobectomy2400 (6.0)6560 (2.9)15.1
Gastrectomy or oesophagectomy1116 (2.8)4547 (2.0)5.2
Nephrectomy1459 (3.6)8921 (4.0)2.1
Cystectomy351 (0.9)2369 (1.1)2.0
Perioperative care
Epidural anaesthesia11 859 (29.6)46 997 (20.9)20.1
Arterial line18 669 (46.6)58 312 (25.9)44.1
Central venous line7561 (18.9)19 693 (8.8)29.6
Pulmonary artery catheter2321 (5.8)4113 (1.8)21.0

*Divided into quarters of approximately equal patient numbers, on basis of total volume of eligible procedures over entire study period.28