Role of immature granulocyte and blood biomarkers in predicting perforated acute appendicitis using machine learning model

Table 1 Comparison of different groups stratified by acute appendicitis status, using pairwise

Variables (median)	Control (n = 41)	AAp (n = 99)	P value	Control (n = 41)	Uncomplicated AAp (n = 65)	P value	Control (n = 41)	Complicated (n = 34)	P value	Uncomplicated AAp (n = 65)	Complicated AAp (n = 34)	P value
Age (year)	43 (37-54)	33 (32-39)	0.003	43 (37-54)	33 (31-40)	0.001	43 (37-54)	36 (32-47)	0.131	33 (31-40)	36 (32-47)	0.091
Platelet	258 (243-291)	248 (237-263)	0.349	258 (243-291)	247 (236-264)	0.381	258 (243-291)	253 (230-276)	0.459	247 (236-264)	253 (230-276)	0.985
Total bilirubin	0.61 (0.49-0.73)	0.73 (0.63-0.87)	0.254	0.61 (0.49-0.73)	0.67 (0.62-0.82)	0.337	0.61 (0.49-0.73)	0.93 (0.61-1.13)	0.187	0.67 (0.62-0.82)	0.93 (0.61-1.13)	0.329
WBC	6.8 (6.5-7.6)	14.5 (13.5-15.3)	< 0.001	6.8 (6.5-7.6)	13.6 (12.9-14.7)	< 0.001	6.8 (6.5-7.6)	15.8 (14.6-16.8)	< 0.001	13.6 (12.9-14.7)	15.8 (14.6-16.8)	0.009
Neutrophil	3.98 (3.70-4.45)	11.5 (10.5-12)	< 0.001	3.98 (3.70-4.45)	10.7 (9.9-12.6)	< 0.001	3.98 (3.70-4.45)	12.2 (11.5-13.8)	< 0.001	10.7 (9.9-12.6)	12.2 (11.5-13.8)	0.047
Lymphocyte	2.5 (2.2-2.6)	2.1 (1.8-2.5)	0.088	2.5 (2.2-2.6)	2 (1.7-2.5)	0.057	2.5 (2.2-2.6)	2.2 (1.8-2.8)	0.400	2 (1.7-2.5)	2.2 (1.8-2.8)	0.401
Monocyte	0.42 (0.39-0.47)	0.69 (0.62-0.73)	< 0.001	0.42 (0.39-0.47)	0.6 (0.6-0.7)	< 0.001	0.42 (0.39-0.47)	0.81 (0.73-0.95)	< 0.001	0.6 (0.6-0.7)	0.81 (0.73-0.95)	0.001
NLR	1.7 (1.6-2.0)	5.81 (5-6.68)	< 0.001	1.7 (1.6-2.0)	6 (4.46-7)	< 0.001	1.7 (1.6-2.0)	5.7 (5.1-7.3)	< 0.001	6 (4.46-7)	5.7 (5.1-7.3)	0.491
LMR	5.97 (5.45-6.64)	2.81 (2.56-3.14)	< 0.001	5.97 (5.45-6.64)	2.9 (2.6-3.5)	< 0.001	5.97 (5.45-6.64)	2.53 (2.16-3.14)	< 0.001	2.9 (2.6-3.5)	2.53 (2.16-3.14)	0.038
MPV	9.6 (9.1-10)	10.3 (10.1-10.6)	0.003	9.60 (9.10-10.2)	10.3 (9.9-10.6)	0.009	9.60 (9.10-10.2)	10.2 (9.8-10.8)	0.009	10.3 (9.9-10.6)	10.2 (9.8-10.8)	0.693
IG (× 103/μL)	0.01 (0.01-0.01)	0.02 (0.02-0.03)	< 0.001	0.01 (0.01-0.01)	0.02 (0.02-0.03)	< 0.001	0.01 (0.01-0.01)	0.03 (0.03-0.06)	< 0.001	0.02 (0.02-0.03)	0.03 (0.03-0.06)	0.001
IG (%)	0.10 (0.10-0.20)	0.1 (0.1-0.2)	< 0.001	0.10 (0.10-0.20)	0.11 (0.10-0.20)	< 0.001	0.10 (0.10-0.20)	0.20 (0.20-0.40)	< 0.001	0.11 (0.10-0.20)	0.20 (0.20-0.40)	0.018
Neutrophil to IG ratio	330 (15-387)	495 (440-570)	< 0.001	330 (15-387)	513 (453-593)	< 0.001	330 (15-387)	442 (383-553)	0.001	513 (453-593)	442 (383-553)	0.182
Ferritin	34 (26-65)	71.3 (35.5-117)	0.070	34 (26-65)	84 (41-124)	0.044	34 (26-65)	30 (25-163)	0.440	84 (41-124)	30 (25-163)	0.490

AAp: Acute appendicitis; IG: Immature granulocytes; MPV: Mean platelet volume; NLR: Neutrophil-to-lymphocyte ratio; LMR: Lymphocyte-to-monocyte ratio; WBC: White blood cell.

Table 2 Results of training and test set metrics of groups based on acute appendicitis status

Groups, metrics (%)	Control vs entire AAp		Uncomplicated vs complicated AAp
	Training set	Test set	Training set	Test set
Accuracy	96.5	96.3	82.5	78.9
Balanced accuracy	95.4	97.4	81.1	80.1
Sensitivity	97.5	94.7	76.9	83.3
Specificity	93.9	100	85.2	76.9
Positive predictive value	97.5	100	71.4	62.5
Negative predictive value	93.9	88.9	88.5	90.9
F1 score	97.5	97.3	74.1	71.4
AUC	96.4	94.7	82.5	79.0
Accuracy	96.5	96.3	82.5	78.9

AAp: Acute appendicitis; AUC: Aera under the curve.

Table 3 Importance of variables in differentiating acute appendicitis from the control group

Variables	Variables importance (%)
WBC	100
Neutrophil	95.14
LMR	76.05
NLR	48.87
Monocyte	35.46
MPV	19.78
Total bilirubin	9.95
IG (%)	7.15
Lymphocyte	6.98
Age	5.89
Neutrophil to IG ratio	4.90
Platelet	3.28
Sex	2.15

WBC: White blood cells; NLR: Neutrophil-to-lymphocyte ratio; LMR: Lymphocyte-to-monocyte ratio; MPV: Mean platelet volume; IG: Immature granulocytes.

Table 4 Importance of variables in differentiating complicated acute appendicitis from the uncomplicated acute appendicitis

Variables	Variables importance (%)
Total bilirubin	100
WBC	96.90
Neutrophil to IG ratio	64.05
NLR	63.53
Ferritin	63.27
Monocyte	62.13
LMR	34.83
MPV	34.53
Lymphocyte	34.33
Platelet	31.07
Neutrophil	29.54
Age	28.75
Sex	0.80
IG	0.38

WBC: White blood cells; NLR: Neutrophil-to-lymphocyte ratio; LMR: Lymphocyte-to-monocyte ratio; MPV: Mean platelet volume; IG: Immature granulocytes.