Factors associated with false fecal immunochemical test results in colorectal cancer screening

Table 2 Characteristics of the study population, n (%)

Characteristics	Total (n = 24890)	Participants with no advanced neoplasm (n = 22586)			Participants with advanced neoplasm (n = 2304)
		False-positive FIT (n = 12471)	True-negative FIT (n = 10115)	P value	False-negative FIT (n = 964)	True-positive FIT (n = 1340)	P value
Age (years), mean ± SD	62.33 ± 7.58	62.54 ± 7.26	61.57 ± 8.02	< 0.001	63.26 ± 7.49	65.32 ± 6.14	< 0.001
40-49	1734 (7.0)	638 (5.1)	1028 (10.2)	< 0.001	55 (5.7)	13 (1.0)	< 0.001
50-59	6506 (26.1)	3404 (27.3)	2653 (26.2)		229 (23.8)	220 (16.4)
60-69	12147 (48.8)	6194 (49.7)	4746 (46.9)		461 (47.8)	746 (55.7)
70-74	4503 (18.1)	2235 (17.9)	1688 (16.7)		219 (22.7)	361 (26.9)
Sex
Male	11911 (47.9)	5865 (47.0)	4612 (45.6)	0.033	596 (61.8)	838 (62.5)	0.761
Female	12979 (52.1)	6606 (53.0)	5503 (54.4)		368 (38.2)	502 (37.5)
Marital status
Married	23907 (96.1)	11984 (96.1)	9706 (96.0)	< 0.001	928 (96.3)	1289 (96.2)	0.172
Unmarried	210 (0.8)	85 (0.7)	106 (1.0)		6 (0.6)	13 (1.0)
Divorced	175 (0.7)	78 (0.6)	83 (0.8)		10 (1.0)	4 (0.3)
Widowed	540 (2.2)	300 (2.4)	191 (1.9)		18 (1.9)	31 (2.3)
Unknown	58 (0.2)	24 (0.2)	29 (0.3)		2 (0.2)	3 (0.2)
Educational level
Primary school or below	5011 (20.1)	3002 (24.1)	1589 (15.7)	< 0.001	149 (15.5)	271 (20.2)	< 0.001
Middle school	16769 (67.4)	8300 (66.6)	6890 (68.1)		659 (68.4)	920 (68.7)
College or above	2945 (11.8)	1109 (8.9)	1546 (15.3)		149 (15.5)	141 (10.5)
Unknown	165 (0.7)	60 (0.5)	90 (0.9)		7 (0.7)	8 (0.6)
Smoking status
Never smoker	19123 (76.8)	9347 (74.9)	8187 (80.9)	< 0.001	708 (73.4)	881 (65.7)	< 0.001
Former smoker	1100 (4.4)	608 (4.9)	360 (3.6)		49 (5.1)	83 (6.2)
Current smoker	4667 (18.8)	2516 (20.2)	1568 (15.5)		207 (21.5)	376 (28.1)
Alcohol consumption
Never drinker	22262 (89.4)	11034 (88.5)	9298 (91.9)	< 0.001	853 (88.5)	1077 (80.4)	< 0.001
Ever drinker	2628 (10.6)	1437 (11.5)	817 (8.1)		111 (11.5)	263 (19.6)
Physical activity
Irregular exercise	13948 (56.0)	7045 (56.5)	5705 (56.4)	0.903	525 (54.5)	673 (50.2)	0.049
Regular exercise	10942 (44.0)	5426 (43.5)	4410 (43.6)		439 (45.5)	667 (49.8)
BMI (kg/m2)
< 25	14126 (56.8)	6790 (54.4)	6086 (60.2)	< 0.001	582 (60.4)	668 (49.9)	< 0.001
25-29.9	9142 (36.7)	4763 (38.2)	3484 (34.4)		336 (34.9)	559 (41.7)
≥ 30	1622 (6.5)	918 (7.4)	545 (5.4)		46 (4.8)	113 (8.4)
Family history of CRC in FDR
No	23095 (92.8)	12069 (96.8)	8862 (87.6)	< 0.001	883 (91.6)	1281 (95.6)	< 0.001
Yes	1795 (7.2)	402 (3.2)	1253 (12.4)		81 (8.4)	59 (4.4)
Hemorrhoids
No	19105 (76.8)	8950 (71.8)	8350 (82.6)	< 0.001	845 (87.7)	960 (71.6)	< 0.001
Yes	5785 (23.2)	3521 (28.2)	1765 (17.4)		119 (12.3)	380 (28.4)
Diverticulum
No	24333 (97.8)	12152 (97.4)	9938 (98.3)	< 0.001	949 (98.4)	1294 (96.6)	0.008
Yes	557 (2.2)	319 (2.6)	177 (1.7)		15 (1.6)	46 (3.4)
Colonoscopy findings
Normal	12057 (48.4)	6566 (52.7)	5491 (54.3)	0.015
Nonadvanced adenoma	10529 (42.3)	5905 (47.3)	4624 (45.7)
Advanced neoplasm	2304 (9.3)				964 (100.0)	1340 (100.0)	-
Advanced adenoma	1780 (7.2)				688 (71.4)	1092 (81.5)	< 0.001
CRC	524 (2.1)				276 (28.6)	248 (18.5)	< 0.001
Stage 0-I	154 (0.6)				64 (6.6)	90 (6.7)	0.001
Stage II-IV	370 (1.5)				212 (22.0)	158 (11.8)	0.001

FIT: Fecal immunological test; BMI: Body mass index; CRC: Colorectal cancer; FDR: First-degree relative.