Predictive modeling for postoperative delirium in elderly patients with abdominal malignancies using synthetic minority oversampling technique

Table 1 Comparative analysis of clinical data between delirium and non-delirium patient groups

Factor	Delirium group (n = 140)	Non-delirium group (n = 471)	Z/t/χ2	P value
Age (yr)	71.00 ± 3.32	70.37 ± 4.45	1.813	0.071
Gender (male/female)	75/65	257/214	0.043	0.836
BMI (kg/m2)	23.41 ± 3.96	24.06 ± 2.34	1.849	0.066
Charlson comorbidity index, n (%)			9.497	0.002
0-2	62 (44.29)	278 (59.02)
≥ 3	78 (55.71)	193 (40.98)
Tumor TMN stage, n (%)			3.722	0.054
I-II	98 (70.00)	367 (77.92)
III-IV	42 (30.00)	104 (22.08)
American Society of Anesthesiologists classification, n (%)			10.999	0.001
I-II	112 (80.00)	307 (65.18)
III-IV	28 (20.00)	164 (34.82)
Nutritional risk, n (%)			0.853	0.356
< 3 patients	78 (55.71)	283 (60.08)
≥ 3 patients	62 (44.29)	188 (39.92)
History of cerebrovascular disease, n (%)	15 (10.71)	24 (5.10)	5.702	0.017
Postoperative hemoglobin level (g/L)	116.34 ± 15.85	114.91 ± 17.33	0.917	0.360
Postoperative blood potassium level (mmol/L)	4.41 ± 0.25	4.39 ± 0.24	0.839	0.403
Postoperative hematocrit (%)	32.17 ± 2.58	32.44 ± 2.17	1.126	0.262
Postoperative cholesterol level (mg/dL)	176.52 ± 50.15	167.56 ± 42.15	1.922	0.056
Postoperative serum creatinine value (μmol/L)	75.43 ± 24.87	72.32 ± 22.89	1.322	0.187
Postoperative alanine transaminase level (U/L)	43.69 ± 4.33	42.94 ± 4.45	1.788	0.075
Surgical method			0.040	0.842
Laparoscopic	124 (88.57)	420 (89.17)
Open	16 (11.43)	51 (10.83)
Surgical duration (min)	228 (203,251)	213 (196,231)	2.293	0.023
Intraoperative bleeding volume (mL)	100 (201,527)	90 (151,350)	1.765	0.079
Perioperative blood transfusion, n (%)	28 (20.00)	49 (10.40)	9.024	0.003
Postoperative pain score	4.01 ± 1.35	3.31 ± 1.10	5.607	< 0.001
Atomization use, n (%)	56 (40.00)	173 (36.73)	0.492	0.483
Ventilator use, n (%)	4 (2.86)	4 (0.85)	3.367	0.067

BMI: Body mass index.

Table 2 Results of multivariate logistic regression analysis

Related indicator	β	SE	Wald	P value	OR	95%CI
						Lower	Upper
Charlson comorbidity index	0.748	0.237	2.985	< 0.001	2.113	1.970	5.266
American Society of Anesthesiologists classification	0.756	0.223	8.945	< 0.001	2.130	1.586	4.691
History of cerebrovascular diseases	1.182	0.226	5.752	< 0.001	3.261	2.293	5.681
Duration of surgery	1.174	0.227	5.124	0.009	3.235	2.440	4.469
Perioperative blood transfusion	1.063	0.219	3.754	< 0.001	2.895	2.194	6.692
Postoperative pain score	1.120	0.379	9.421	< 0.001	3.065	2.610	4.725

SE: Standard error; OR: Odds ratio; CI: Confidence interval; β: Beta coefficient.

Table 3 Results of multivariate logistic regression analysis enhanced by synthetic minority oversampling technique

Related indicator	β	SE	Wald	P value	OR	95%CI
						Lower	Upper
Charlson comorbidity index	0.527	0.522	6.313	0.012	1.693	1.494	5.388
American Society of Anesthesiologists classification	0.544	0.576	10.844	0.009	1.723	1.536	6.775
History of cerebrovascular diseases	1.167	0.613	10.142	0.003	3.212	1.930	3.397
Duration of surgery	1.154	0.565	5.685	0.025	3.170	2.326	7.894
Perioperative blood transfusion	1.007	0.558	13.022	0.001	2.737	1.247	3.682
Postoperative pain score	1.132	0.822	11.912	0.001	3.101	2.092	12.064

SE: Standard error; OR: Odds ratio; CI: Confidence interval; β: Beta coefficient.