Risk modeling of delayed postoperative bleeding after endoscopic submucosal dissection for early colorectal cancer and precancerous lesions

Table 1 Univariate analysis of risk factors for delayed postoperative bleeding in patients with early colorectal cancer and precancerous lesions, n (%)

Factors	n	DPOB group (n = 30)	Non-DPOB group (n = 272)	χ2	P value
Gender				0.822	0.365
Male	178	20 (66.67)	158 (58.09)
Female	124	10 (33.33)	114 (41.91)
Age (years)				1.276	0.259
< 60	122	15 (50.00)	107 (39.34)
≥ 60	180	15 (50.00)	165 (60.66)
Comorbidities
Hypertension	30	4 (13.33)	26 (9.56)	0.430	0.512
Diabetes	25	2 (6.67)	23 (8.46)	0.114	0.736
COPD	12	2 (6.67)	10 (3.68)	0.633	0.426
Smoking	73	5 (16.67)	68 (25.00)	1.024	0.312
Alcohol consumption	68	9 (30.00)	59 (21.69)	1.069	0.301
Number of lesions				7.294	0.007
Single	215	15 (50.00)	200 (73.53)
Multiple	87	15 (50.00)	72 (26.47)
Lesion size (cm)				5.787	0.016
< 3	173	11 (36.67)	162 (59.56)
≥ 3	129	19 (63.33)	110 (40.44)
Lesion location				7.706	0.006
Colon	163	9 (30.00)	154 (56.62)
Rectum	139	21 (70.00)	118 (43.38)
Degree of submucosal fibrosis				5.434	0.020
None or mild	282	25 (83.33)	257 (94.49)
Severe	20	5 (16.67)	15 (5.51)
Intraoperative bleeding	107	16 (53.33)	91 (33.46)	4.667	0.031

DPOB: Delayed postoperative bleeding; COPD: Chronic obstructive pulmonary disease.

Table 2 Variable assignment

Factors	Variables	Assignments
DPOB	Y	No: 0, yes: 1
Number of lesions	X1	Single: 0, multiple: 1
Lesion size (cm)	X2	< 3: 0, ≥ 3: 1
Lesion location	X3	Colon: 0, rectum: 1
Degree of submucosal fibrosis	X4	None or mild: 0, severe: 1
Intraoperative bleeding	X5	No: 0, yes: 1

DPOB: Delayed postoperative bleeding.

Table 3 Multivariate analysis of risk factors for delayed postoperative bleeding in patients with early colorectal cancer and precancerous lesions

Factors	β	SE	Wald	P value	Exp (β)	95%CI
Number of lesions	0.904	0.414	4.756	0.029	2.469	1.096-5.563
Lesion size (cm)	0.856	0.417	4.210	0.040	2.353	1.039-5.328
Lesion location	1.145	0.437	6.861	0.009	3.144	1.334-7.407
Degree of submucosal fibrosis	1.490	0.628	5.639	0.018	4.439	1.297-15.188
Intraoperative bleeding	0.651	0.417	2.438	0.118	1.917	0.847-4.338

CI: Confidence interval.

Table 4 Receiver operating characteristic analysis data for the predictive performance of the risk model for delayed postoperative bleeding

Factor	AUC	SE	95%CI	Cutoff	Specificity (%)	Sensitivity (%)
Modeling group	0.831	0.058	0.717-0.944	0.26	96.13	60.00
Validation group	0.821	0.080	0.664-0.979	0.13	75.82	90.00

AUC: Area under the curve; CI: Confidence interval.

Table 5 10-fold cross-validation data

Sequence number	AUC of the validation set
1	0.877
2	0.786
3	0.835
4	0.733
5	0.722
6	0.774
7	0.748
8	0.810
9	0.916
10	0.746
Mean	0.795 (95%CI: 0.702-0.887)

AUC: Area under the curve; CI: Confidence interval.