Personal predictive model based on systemic inflammation markers for estimation of postoperative pancreatic fistula following pancreaticoduodenectomy

Table 1 Baseline demographic and clinicopathological characteristics of patients

Variables	Training set				Testing set
	Overall (n = 432)	Non-POPF (n = 354)	POPF (n = 78)	P value	Overall (n = 186)	Non-POPF (n = 166)	POPF (n = 20)	P value
Age, median (IQR)	55.0 (49.0–61.0)	55.0 (49.0–61.0)	53.0 (47.25–61.0)	0.147	55.0 (50.0–60.0)	55.0 (50.0–60.0)	51.50 (45.75–59.50)	0.182
BMI, median (IQR)	23.10 (21.80–24.60)	22.80 (21.50–24.20)	25.0 (23.33–26.92)	< 0.001	22.85 (21.72–24.30)	22.70 (21.52–23.98)	24.35 (22.88–26.13)	< 0.001
Gender (%)
Male	283 (65.5)	227 (64.1)	56 (71.8)	0.247	127 (68.3)	110 (66.3)	17 (85.0)	0.148
Female	149 (34.5)	127 (35.9)	22 (28.2)		59 (31.7)	56 (33.7)	3 (15.0)
Smoking (%)
Yes	198 (45.8)	143 (40.4)	55 (70.5)	< 0.001	89 (47.8)	76 (45.8)	13 (65.0)	0.165
No	234 (54.2)	211 (59.6)	23 (29.5)		97 (52.2)	90 (54.2)	7 (35.0)
Drinking history (%)
Yes	129 (29.9)	78 (22.0)	51 (65.4)	< 0.001	54 (29.0)	40 (24.1)	14 (70.0)	< 0.001
No	303 (70.1)	276 (78.0)	27 (34.6)		132 (71.0)	126 (75.9)	6 (30.0)
Diabetes (%)
Yes	110 (25.5)	49 (13.8)	61 (78.2)	< 0.001	44 (23.7)	30 (18.1)	14 (70.0)	< 0.001
No	322 (74.5)	305 (86.2)	17 (21.8)		142 (76.3)	136 (81.9)	6 (30.0)
Hypertension (%)
Yes	164 (38.0)	129 (36.4)	35 (44.9)	0.208	59 (31.7)	49 (29.5)	10 (50.0)	0.108
No	268 (62.0)	225 (63.6)	43 (55.1)		127 (68.3)	117 (70.5)	10 (50.0)
Abdominal operation (%)
Yes	130 (30.1)	103 (29.1)	27 (34.6)	0.409	53 (28.5)	47 (28.3)	6 (30.0)	1
No	302 (69.9)	251 (70.9)	51 (65.4)		133 (71.5)	119 (71.7)	14 (70.0)
Remnant texture (%)
Soft	121 (28.0)	62 (17.5)	59 (75.6)	< 0.001	44 (23.7)	27 (16.3)	17 (85.0)	< 0.001
Hard	311 (72.0)	292 (82.5)	19 (24.4)		142 (76.3)	139 (83.7)	3 (15.0)
Blood transfusion (%)
Yes	232 (53.7)	188 (53.1)	44 (56.4)	0.686	96 (51.6)	84 (50.6)	12 (60.0)	0.577
No	200 (46.3)	166 (46.9)	34 (43.6)		90 (48.4)	82 (49.4)	8 (40.0)
Anemia (%)
Yes	218 (50.5)	179 (50.6)	39 (50.0)	1	84 (45.2)	69 (41.6)	15 (75.0)	0.009
No	214 (49.5)	175 (49.4)	39 (50.0)		102 (54.8)	97 (58.4)	5 (25.0)
Lesion size (%), cm
> 3	182 (42.1)	125 (35.3)	57 (73.1)	< 0.001	67 (36.0)	54 (32.5)	13 (65.0)	0.009
≤ 3	250 (57.9)	229 (64.7)	21 (26.9)		119 (64.0)	112 (67.5)	7 (35.0)
Pancreatic duct diameter (%), mm
< 3	154 (35.6)	93 (26.3)	61 (78.2)	< 0.001	63 (33.9)	49 (29.5)	14 (70.0)	0.001
≥ 3	278 (64.4)	261 (73.7)	17 (21.8)		123 (66.1)	117 (70.5)	6 (30.0)
ASA classification (%)
I + II	231 (53.5)	188 (53.1)	43 (55.1)	0.843	85 (45.7)	78 (47.0)	7 (35.0)	0.436
III + IV	201 (46.5)	166 (46.9)	35 (44.9)		101 (54.3)	88 (53.0)	13 (65.0)
CRP, median (IQR), mg/L	32.0 (22.0–44.0)	29.0 (21.0–38.0)	88.50 (56.0–120.0)	< 0.001	30.0 (22.0–40.0)	29.0 (21.0–38.0)	84.50 (42.25–109.25)	< 0.001
WBC, median (IQR), 109	5.70 (5.30–6.30)	5.70 (5.20–6.20)	6.0 (5.60–6.60)	< 0.001	5.70 (5.20–6.30)	5.60 (5.20–6.20)	6.40 (5.52–6.82)	0.002
PCT, median (IQR), μg/L	0.54 (0.37–0.68)	0.49 (0.34–0.61)	1.06 (0.78–1.21)	< 0.001	0.52 (0.37–0.67)	0.49 (0.35–0.63)	0.84 (0.68–1.09)	< 0.001
AGR, median (IQR)	1.50 (1.30–1.60)	1.50 (1.40–1.60)	1.35 (1.20–1.40)	< 0.001	1.50 (1.30–1.60)	1.50 (1.40–1.60)	1.35 (1.17–1.52)	0.003
PNI, median (IQR)	49.60 (48.10–51.23)	49.90 (48.32–51.60)	48.60 (47.35–49.60)	< 0.001	50.10 (48.40–51.48)	50.30 (48.42–51.60)	49.30 (46.85–50.37)	0.02
Neutrophil count, median (IQR), 109	4.02 (3.49–4.59)	4.18 (3.70–4.68)	3.36 (3.03–3.74)	< 0.001	3.94 (3.51–4.54)	4.03 (3.57–4.57)	3.46 (3.11–3.76)	< 0.001
Lymphocyte count, median (IQR), 109	1.64 (1.51–1.78)	1.63 (1.50–1.76)	1.79 (1.60–1.94)	< 0.001	1.64 (1.53–1.76)	1.63 (1.52–1.73)	1.83 (1.69–1.98)	< 0.001
Platelet count, median (IQR), 109	230.0 (208.0–252.0)	236.0 (213.0–255.0)	206.0 (185.25–229.75)	< 0.001	229.0 (206.0–253.75)	232.0 (208.25–257.75)	200.0 (182.50–225.0)	< 0.001
Monocyte count, median (IQR), 109	0.52 (0.45–0.60)	0.55 (0.47–0.62)	0.44 (0.39–0.49)	< 0.001	0.53 (0.46–0.61)	0.54 (0.47–0.62)	0.48 (0.42–0.52)	0.003
Hemoglobin, median (IQR), g/L	132.0 (124.0–139.0)	130.0 (121.25–138.0)	138.0 (133.0–142.75)	< 0.001	132.0 (126.0–140.0)	132.0 (126.0–139.75)	134.50 (130.0–141.0)	0.026
NLR, median (IQR)	2.0 (1.70–2.30)	1.90 (1.70–2.20)	2.70 (2.22–3.10)	< 0.001	2.0 (1.70–2.30)	1.90 (1.60–2.20)	2.80 (2.42–3.05)	< 0.001
NAR, median (IQR)	0.08 (0.07–0.09)	0.08 (0.07–0.09)	0.60 (0.30–0.88)	< 0.001	0.08 (0.07–0.09)	0.08 (0.07–0.09)	0.65 (0.38–0.80)	< 0.001
PLR, median (IQR)	136.20 (116.68–157.43)	143.85 (123.23–161.70)	113.15 (102.58–128.0)	< 0.001	136.45 (120.62–155.80)	141.0 (121.22–159.78)	120.15 (104.78–128.57)	< 0.001
LMR, median (IQR)	3.40 (2.90–3.80)	3.30 (2.80–3.70)	3.90 (3.52–4.70)	< 0.001	3.50 (3.0–3.80)	3.40 (2.90–3.70)	4.15 (3.75–4.48)	< 0.001
HALP, median (IQR)	53.95 (51.08–56.50)	52.90 (50.50–55.20)	72.75 (69.32–75.25)	< 0.001	52.45 (50.40–55.18)	51.95 (50.10–54.30)	70.10 (68.18–72.62]	< 0.001

POPF: Postoperative pancreatic fistula; IQR: Inter-quartile range; BMI: Body mass index; ASA: American Society of Anesthesiologists; CRP: C-reactive protein; WBC: White blood cell; PCT: Procalcitonin; AGR: Albumin-to-globulin ratio; PNI: Prognostic nutrition index; NLR: Neutrophil-to-lymphocyte ratio; NAR: Neutrophil-to-albumin ratio; PLR: Platelet-to-lymphocyte ratio; LMR: Lymphocyte-to-monocyte ratio; HALP: Hemoglobin level × albumin level × lymphocyte count/platelet count ratio.

Table 2 The operating characteristic curve analyses for each machine learning-based model

Model	AUC		No. of candidate variables
	Mean	95%CI
RFC	0.897	0.370–1.424	7
SVM	0.726	0.191–1.261	8
DT	0.807	0.250–1.364	8
ANN	0.882	0.321–1.443	7
XGboost	0.793	0.270–1.316	9

95%CI: 95% confidence interval; RFC: Random forest classifier; SVM: Support vector machine; DT: Decision tree; ANN: Artificial neutral network; XGboost: Extreme gradient boosting; AUC: Area under curve.