Table 2.

Median serum amylase on postoperative day 1 and median drain fluid amylase on postoperative day 2 stratified by patient characteristics

	Median (IQR) serum amylase on POD 1 (U/L)	p-value	Median (IQR) drain amylase on POD 2 (U/L)	p-value
Age
< 70	121 (50–335)	0.682	162 (33–1304)	0.753
≥ 70	117 (56–322)		163 (35–803)
Gender
Male	128 (56–308)	0.481	160 (36–1062)	0.494
Female	128 (56–308)		190 (34–1498)
Body mass index
< 25	103 (49–310)	0.113	114 (27–706)	<0.001
≥ 25	142 (56–345)		270 (61–1787)
ASA score
1–2	125 (53–337)	0.521	179 (35–1473)	0.362
3–4	105 (50–286)		134 (34–561)
Preoperative biliary drainage
No	160 (56–364)	0.203	270 (44–1584)	0.051
Yes	101 (52–293)		125 (32–1090)
Preoperative chemoradiotherapy
No	142 (57–354)	<0.001	221 (41–1420)	<0.001
Yes	55 (28–76)		20 (12–67)
Diameter pancreatic duct
≤ 3 mm	237 (79–502)	<0.001	528 (104–2086)	<0.001
> 3mm	72 (36–163)		49 (20–270)
Pancreatic texture
Soft/normal	258 (111–545)	<0.001	733 (162–2767)	<0.001
Hard/fibrotic	61 (31–120)		39 (20–155)
High-risk pathology†
No	73 (36–142)	<0.001	54 (21–253)	<0.001
Yes	220 (71–467)		454 (76–1914)
Malignant pathology
No	212 (75–509)	<0.001	672 (63–1996)	0.004
Yes	93 (49–270)		133 (32–769)
Intra-operative blood loss
≤ 1500 ml	115 (48–315)	0.038	162 (33–1231)	0.873
> 1500 ml	140 (61–429)		175 (35–989)

^†High-risk pathology included all pathological diagnosis except pancreatic ductal adenocarcinoma and chronic pancreatitis

POD postoperative day, IQR interquartile range