Stratified computed tomography findings improve diagnostic accuracy for appendicitis

Table 1 Patient characteristics n (%)

Characteristics	Total population	Negative appendicitis	Pathologically proven appendicitis	P value
	(n = 224)	(n = 47)	(n = 177)
Age (yr)				0.052
< 15	26 (11.6)	10 (21.3)	16 (9.0)
15-64	169 (75.4)	33 (70.2)	136 (76.9)
≥ 65	29 (13.0)	4 (8.5)	25 (14.1)
Gender				0.092
Male	88 (39.3)	13 (27.7)	75 (42.4)
Female	136 (60.7)	34 (72.3)	102 (57.6)
Body mass index (kg/m2)				0.635
< 20	52 (27.1)	12 (31.6)	40 (26.0)
20-25	106 (55.2)	21 (55.2)	85 (55.2)
> 25	34 (17.7)	5 (13.2)	29 (18.8)
Comorbidity				0.350
Charlson index = 0	217 (96.9)	47 (100.0)	170 (96.0)
Charlson index > 0	7 (3.1)	0 (0.0)	7 (4.0)
Symptom duration before presentation				0.740
< 72 h	129 (58.1)	26 (55.3)	103 (58.9)
≥ 72 h	93 (41.9)	21 (44.7)	72 (41.1)
Body temperature (°C)				0.755
< 37.8	119 (88.8)	28 (87.5)	91 (89.2)
≥ 37.8	15 (11.2)	4 (12.5)	11 (10.8)
Presenting symptom				0.507
Abdominal pain	219 (97.8)	47 (100.0)	172 (97.2)
Indigestion	1 (0.4)	0 (0.0)	1 (0.6)
Fever/chill	4 (1.8)	0 (0.0)	4 (2.2)
Pain migration				0.507
No	114 (53.3)	26 (57.8)	88 (52.1)
Yes	100 (46.7)	19 (42.2)	81 (47.9)
Degree of tenderness				0.383
Mild	4 (1.8)	0 (0.0)	4 (2.3)
Moderate	217 (96.9)	47 (100.0)	170 (96.0)
Severe	3 (1.3)	0 (0.0)	3 (1.7)
RLQ localization of pain				0.559
Discrete	205 (91.5)	42 (89.4)	163 (92.1)
Obscure	19 (8.5)	5 (10.6)	14 (7.9)
Lab findings, median (range)
WBC count (× 103/mm3)	9.55 (4.0-29.1)	9.3 (4.6-25.9)	9.6 (4.0-29.1)	0.833
Platelet count (× 103/mm3)	250 (157- 564)	277 (202-564)	241 (157-341)	0.005
Creatinine (mg/dL)	0.64 (0.41- 1.11)	0.56 (0.41-0.69)	0.70 (0.46-1.11)	0.036
Albumin (g/dL)	4.30 (3.3-5.4)	4.40 (3.3-5.2)	4.30 (3.3-5.4)	0.989
Total bilirubin (mg/dL)	0.50 (0.2-1.5)	0.55 (0.2-1.5)	0.77 (0.2-2.2)	0.020
Neutrophil fraction				0.359
< 80%	160 (72.4)	36 (78.3)	124 (70.9)
≥ 80%	61 (27.6)	10 (21.7)	51 (29.1)

Data from patients receiving operations for suspicion of appendicitis with computed tomography findings that were negative or equivocal for appendicitis. RLQ: Right low quadrant of abdomen; WBC: White blood cells.