Quantifying abdominal abscess burden using area under the curve methods inspired by dehiscence, infection/inflammation, seroma, hematoma classification

Table 1 Baseline patient characteristics

Characteristics	Total (n)	n (%)
Age, years, median (IQR)	59	65 (59-77)
Male	59	36 (61.0)
ASA classification	59
I		7 (11.9)
II		39 (66.1)
III		12 (20.3)
IV		1 (1.7)
Smoker	59	32 (54.2)
Diabetes mellitus	59	15 (25.4)
BMI, kg/m2, median (IQR)	57	22.2 (20.4-24.5)
Malnutrition (GLIM criteria)	59	28 (47.5)
Malignancy	59	19 (32.2)
Emergency surgery	59	36 (61.0)
Laparotomy	59	12 (20.3)
Operative time, minutes, median (IQR)	59	168 (93-275)
Intraoperative blood loss (mL)	59	15 (5-100)
Intraoperative drain placement	59	33 (55.9)
Wound class	59
Clean operation		1 (1.7)
Clean-contaminated operation		19 (32.2)
Contaminated operation		5 (8.5)
Dirty/infected operation		34 (57.6)
Procedure	59
Appendectomy		19 (32.2)
Colorectal surgery		24 (40.7)
Upper gastrointestinal surgery		6 (10.2)
Hepatobiliary and pancreatic surgery		7 (11.9)
Others		3 (5.1)

ASA: American Society of Anesthesiologists; BMI: Body mass index; GLIM: Global leadership initiative on malnutrition; IQR: Interquartile range.

Table 2 Comparisons between the high- and low-area-under-the-curve groups, n (%)

Characteristics	Variable coding	High-AUC (n = 16)	Low-AUC (n = 43)	Odds ratio (95%CI)	P value
Age, years, median (IQR)	Per 1-year	74 (69.3-76.3)	68 (55.0-75.5)	1.04 (1.00-1.10)	0.0653
Male	Yes/No	9 (56.3)	27 (62.8)	1.31 (0.40-4.22)	0.7661
ASA score	III, IV/I, II	5 (31.3)	8 (18.6)	1.99 (0.51-7.31)	0.3106
Smoker	Yes/No	6 (37.5)	26 (60.5)	0.39 (0.11-1.25)	0.1473
Diabetes mellitus	Yes/No	8 (50.0)	7 (16.3)	5.14 (1.46-19.2)	0.0161
BMI, kg/m2, median (IQR)	Per 1-unit	22.3 (20.3-24.7)	22.2 (20.5-24.3)	0.94 (0.77-1.10)	0.8036
Malnutrition (GLIM criteria)	Yes/No	2 (12.5)	5 (11.6)	1.08 (0.14-5.70)	1.0000
Malignancy	Yes/No	9 (56.3)	16 (37.21)	2.17 (0.68-7.19)	0.2410
Emergency	Yes/No	6 (37.5)	30 (69.77)	0.26 (0.07-0.84)	0.0358
Laparotomy	Yes/No	5 (31.3)	7 (16.3)	2.34 (0.59-8.89)	0.2766
Operative time, minutes, median (IQR)	Per 1-minute	198 (122.8-266.8)	144 (78.5-271.5)	1.00 (0.97-1.01)	0.2228
Intraoperative blood loss, mL, median (IQR)	Per 1-mL	80 (25-115)	15 (5-40)	1.00 (1.00-1.01)	0.0074
Intraoperative drain placement	Yes/No	9 (56.3)	24 (55.8)	0.90 (0.28-3.01)	1.0000
Infected operation	Yes/No	9 (56.3)	25 (58.1)	0.93 (0.29-3.03)	1.0000
Time to abscess diagnosis, days, meidan (IQR)	Per 1-day	9.5 (5.8-12.5)	7 (5.0-9.0)	1.09 (1.00-1.22)	0.0915
Diameter of abscess > 5 cm	Yes/No	11 (68.8)	15 (34.9)	4.11 (1.25-15.2)	0.0371
Multiple abscesses	Yes/No	2 (12.5)	10 (23.3)	0.47 (0.07-2.09)	0.4822
Postoperative hospital stays, days, median (IQR)	Per 1-day	24 (17.8-32.0)	17 (11.5-21.5)	1.07 (1.01-1.14)	0.0070
Duration of antibiotics, days, median (IQR)	Per 1-day	17 (13.3-21.3)	9 (7.0-13.0)	1.26 (1.11-1.51)	0.0003
Abscess to discharge, days, median (IQR)	Per 1-day	16 (13.8-25.3)	11 (8.5-16.0)	1.08 (1.02-1.16)	0.0074

Time to abscess diagnosis: Number of days from surgery to abscess diagnosis; abscess to discharge: Number of days from abscess diagnosis to hospital discharge; AUC: Area under the curve; ASA: American Society of Anesthesiologists; BMI: Body mass index; GLIM: Global Leadership Initiative on Malnutrition; IQR: Interquartile range.