Impact of surgical volume on nationwide hospital mortality after pancreaticoduodenectomy

Table 1 Patient and hospital characteristics by surgical volume

Characteristics	Very-low (n = 92)	Low (n = 20)	Medium (n = 10)	High (n = 3)	Very-high (n = 1)	P value
Age (mean ± SD) (yr)	62.2 ± 10.7	62.1 ± 10.2	62.1 ± 10.5	61.2 ± 9.9	59.9 ± 10.3	0.077
Sex ratio (M:F)	1.5	1.3	1.5	1.6	1.6	0.282
Admission route						< 0.001
Outpatient department (%)	803 (78.6)	774 (77.0)	788 (77.3)	901 (84.4)	593 (68.9)
Emergency room (%)	218 (21.4)	231 (23.0)	232 (22.7)	167 (15.6)	268 (31.1)
Charlson comorbidity score						0.193
< 3 (%)	683 (66.9)	651 (64.8)	680 (66.7)	667 (62.5)	554 (64.3)
≥ 3 (%)	338 (33.1)	354 (35.2)	340 (33.3)	401 (37.5)	307 (35.7)
Type of medical security						< 0.001
Health insurance (%)	919 (90.0)	925 (92.0)	955 (93.6)	1048 (98.1)	841 (97.7)
Medical aid (%)	102 (10.0)	80 (8.0)	65 (6.4)	20 (1.9)	20 (2.3)
Type of operation						< 0.001
CPD (%)	604 (59.2)	420 (41.8)	361 (35.4)	325 (30.4)	301 (35.0)
PPPD (%)	417 (40.8)	585 (58.2)	659 (64.6)	743 (69.6)	560 (65.0)
Average annual volume	< 10	10-18	19-35	54-111	215	9.91

¹Denotes average annual surgical volume of all hospitals. SD: Standard deviation; M: Male; F: Female; CPD: Classical pancreaticoduodenectomy; PPPD: Pylorus-preserving pancreaticoduodenectomy.