Machine learning-based prediction of postoperative mortality risk after abdominal surgery

Table 1 Univariate analysis of postoperative death in patients undergoing abdominal surgery, mean ± SD/n (%)

Index	Death (n = 52)	Survival (n = 178)	t/χ2	P value
Sex			0.025	0.875
Male	27 (51.92)	95 (53.37)
Female	25 (48.08)	83 (46.63)
Age, years	59.21 ± 5.26	57.34 ± 6.14	1.990	0.048
BMI, kg/m2	23.50 ± 2.73	23.89 ± 2.95	-0.839	0.403
Emergency surgery			1.525	0.217
Yes	19 (36.54)	48 (26.97)
No	33 (63.46)	130 (73.03)
Previous abdominal surgery			0.073	0.787
Yes	14 (26.92)	45 (25.28)
No	38 (73.08)	133 (74.72)
Smoking			0.303	0.582
Yes	10 (19.23)	40 (22.47)
No	42 (80.77)	138 (77.53)
Drinking			0.014	0.904
Yes	24 (46.15)	81 (45.51)
No	28 (53.85)	97 (54.49)
Hypertension			0.115	0.735
Yes	5 (9.62)	19 (10.67)
No	47 (90.38)	159 (89.33)
Diabetes			0.031	0.861
Yes	18 (34.62)	59 (33.15)
No	34 (65.38)	119 (66.85)
Surgical approach			7.209	0.007
Laparoscopic	23 (44.23)	111 (62.36)
Laparotomy/conversion	29 (55.77)	67 (37.64)
ASA classification			10.011	0.040
I	3 (5.77)	9 (5.06)
II	27 (51.92)	130 (73.03)
III	12 (23.08)	26 (14.61)
IV	9 (17.31)	8 (4.49)
V	1 (1.92)	5 (2.81)
Abnormal ECG			1.792	0.181
Yes	27 (51.92)	73 (41.01)
No	25 (48.08)	105 (58.99)
Preoperative complications			8.136	0.004
Yes	16 (30.77)	26 (14.61)
No	36 (69.23)	152 (85.39)
SBP, mmHg	127.94 ± 7.53	128.59 ± 6.04	-0.642	0.522
DBP, mmHg	74.44 ± 5.27	75.20 ± 6.15	-0.809	0.420
D-dimer, mg/L	1.18 ± 0.35	1.13 ± 0.20	1.120	0.264
PT, second	12.29 ± 3.15	11.90 ± 2.38	0.948	0.344
APTT, second	32.33 ± 2.83	27.04 ± 3.46	10.077	< 0.001
FBG, g/L	3.31 ± 0.74	3.38 ± 0.89	-0.503	0.616
AST, IU/L	43.50 ± 14.51	37.46 ± 9.72	3.489	0.001
BUN, mmol/L	5.63 ± 0.63	5.53 ± 0.69	0.993	0.322
TBA, μmol/L	10.55 ± 2.32	10.12 ± 1.96	1.323	0.187
ALB, g/L	34.99 ± 5.94	35.81 ± 5.45	-0.934	0.351
A/G ratio	1.24 ± 0.29	1.32 ± 0.27	-1.800	0.073
Cre, μmol/L	69.61 ± 9.07	68.25 ± 8.09	1.036	0.301
TBIL, μmol/L	26.07 ± 3.82	20.38 ± 4.42	8.400	< 0.001
Blood calcium, mmol/L	2.17 ± 0.14	2.16 ± 0.17	0.447	0.655
Blood sodium, mmol/L	140.13 ± 3.35	140.98 ± 3.29	-1.654	0.099
Blood potassium, mmol/L	3.82 ± 0.38	3.81 ± 0.40	0.103	0.918
NEUT, × 109/L	5.13 ± 0.79	4.98 ± 0.56	1.486	0.139
LYMPH, × 109/L	1.21 ± 0.25	1.28 ± 0.33	-1.393	0.165
WBC, × 109/L	11.84 ± 3.94	9.72 ± 3.44	3.774	< 0.001
PLT, × 109/L	191.35 ± 63.09	194.91 ± 50.82	-0.420	0.675
Hb, g/L	116.75 ± 5.89	116.40 ± 5.78	0.384	0.701
Operation type
Emergency	2 (3.85)	1 (0.56)	3.104	0.541
Urgent	9 (17.31)	36 (20.22)
Semi-urgent	12 (23.08)	45 (25.28)
Non-urgent	11 (21.15)	28 (15.73)
Elective	18 (34.62)	68 (38.20)
Operation time, hour	2.52 ± 1.09	2.54 ± 1.03	-0.103	0.918

BMI: Body mass index; ECG: Electrocardiogram; ASA: American Society of Anesthesiologists; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; PT: Prothrombin time; APTT: Activated partial thromboplastin time; FBG: Fibrinogen; AST: Aspartate aminotransferase; BUN: Blood urea nitrogen; TBA: Total bile acid; ALB: Albumin; A/G: Albumin/globulin ratio; Cre: Creatinine; TBIL: Total bilirubin; NEUT: Neutrophils; LYMPH: Lymphocytes; WBC: White blood cell; PLT: Platelets; Hb: Hemoglobin.