Table 1: Preoperative characteristics.

CharacteristicsLow-volume surgeon ()
Number of cases (%)
High-volume surgeon ()
Number of cases (%)
value

Gender
 Male 234 (52)184 (57)0.12
 Female219 (48)137 (43)

Age in years
 Median (95% CI)69 (46–92)69 (48–90)
 <5030 (7)11 (3)0.66
 50–75276 (61)218 (68)
 >75147 (32)92 (29)

ASA-classification [16]
 1101 (23)57 (18)<0.001
 2218 (47)192 (60)
 3112 (25)69 (21)
 422 (5)3 (1)

Comorbidity
 No147 (33)102 (32)0.83
 Yes305 (67)219 (68)
  Cardiac
   No367 (81)251 (78)0.30
   Yes85 (19)70 (22)
  Pulmonary
   No411 (91)285 (89)0.33
   Yes41 (9)36 (11)
  Diabetes
   No393 (87)293 (91)0.06
   Yes59 (13)28 (9)

BMI
 Median (95% CI)26 (18.5–32.5)26 (18.7–32.7)0.54

Surgical technique
 Open187 (41)72 (22)<0.001
 Laparoscopic 266 (59)249 (78)

Type of resection
 Right colon149 (33)86 (27)<0.001
 Transversum26 (6)6 (2)
 Left colon49 (11)29 (9)
 Sigmoid 109 (24)95 (29)
 LAR95 (21)70 (22)
 APR25 (5)35 (11)

Neoadjuvant radiotherapy (rectum only)
 No 74 (56)52 (45)0.10
 Yes59 (44)63 (55)

Neoadjuvant chemoradiotherapy (rectum only)
 No130 (98)90 (78)<0.001
 Yes3 (2)25 (22)

American Society of Anesthesiology; body mass index; low anterior resection; abdominoperineal resection; 95% confidence interval.