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

Table 1 Characteristics of participants with complete fecal immunological test data in Tianjin Colorectal Cancer Screening Program, 2012-2020, n (%)

Characteristic	Total (n = 4129947)	Positive FIT (n = 88687)	Negative FIT (n = 4041260)	P value
Age (years), mean ± SD	60.80 ± 8.35	63.14 ± 7.69	60.75 ± 8.36	< 0.001
40-49	460401 (11.1)	5220 (5.9)	455181 (11.3)	< 0.001
50-59	1337212 (32.4)	22160 (25.0)	1315052 (32.5)
60-69	1607369 (38.9)	40561 (45.7)	1566808 (38.8)
70-74	724965 (17.6)	20746 (23.4)	704219 (17.4)
Sex
Male	2197221 (53.2)	46723 (52.7)	2150498 (53.2)	0.002
Female	1932726 (46.8)	41964 (47.3)	1890762 (46.8)
Marital status
Married	3941435 (95.4)	84617 (95.4)	3856818 (95.4)	< 0.001
Unmarried	47806 (1.2)	799 (0.9)	47007 (1.2)
Divorced	29190 (0.7)	598 (0.7)	28592 (0.7)
Widowed	91779 (2.2)	2551 (2.9)	89228 (2.2)
Missing	19737 (0.5)	122 (0.1)	19615 (0.5)
Educational level
Primary school or below	1052467 (25.5)	26043 (29.4)	1026424 (25.4)	< 0.001
Middle school	2621411 (63.5)	55341 (62.4)	2566070 (63.5)
College or above	411895 (10.0)	7011 (7.9)	404884 (10.0)
Missing	44174 (1.1)	292 (0.3)	43882 (1.1)
Occupation
Office clerks and related personnel	158551 (3.8)	2894 (3.3)	155657 (3.9)	< 0.001
Persons in charge of state organizations, large organizations, enterprises and institutions	750333 (18.2)	11083 (12.5)	739250 (18.3)
Soldiers	1555 (0.0)	38 (0.0)	1517 (0.0)
Agriculture workers	1003000 (24.3)	26694 (30.1)	976306 (24.2)
Business and service personnel	286538 (6.9)	3791 (4.3)	282747 (7.0)
Production, transportation, equipment and related personnel	475649 (11.5)	13577 (15.3)	462072 (11.4)
Professional and technical personnel	707738 (17.1)	10571 (11.9)	697167 (17.3)
Others	248457 (6.0)	5777 (6.5)	242680 (6.0)
Unemployed	475567 (11.5)	14130 (15.9)	461437 (11.4)
Missing	22559 (0.5)	132 (0.1)	22427 (0.6)
Smoking status
Never smoker	2003864 (48.5)	41124 (46.4)	1962740 (48.6)	< 0.001
Former smoker	76977 (1.9)	2675 (3.0)	74302 (1.8)
Current smoker	489557 (11.9)	12751 (14.4)	476806 (11.8)
Missing	1559549 (37.8)	32137 (36.2)	1527412 (37.8)
Alcohol consumption
Never drinker	2349521 (56.9)	49412 (55.7)	2300109 (56.9)	< 0.001
Ever drinker	219447 (5.3)	7093 (8.0)	212354 (5.3)
Missing	1560979 (37.8)	32182 (36.3)	1528797 (37.8)
Physical activity
Irregular exercise	1620846 (39.2)	32472 (36.6)	1588374 (39.3)	< 0.001
Regular exercise	948229 (23.0)	24060 (27.1)	924169 (22.9)
Missing	1560872 (37.8)	32155 (36.3)	1528717 (37.8)
BMI (kg/m2)
< 25	1574985 (38.1)	31170 (35.1)	1543815 (38.2)	< 0.001
25-29.9	847303 (20.5)	21280 (24.0)	826023 (20.4)
≥ 30	150992 (3.7)	4276 (4.8)	146716 (3.6)
Missing	1556667 (37.7)	31961 (36.0)	1524706 (37.7)
Chronic diarrhea
No	4012945 (97.2)	77784 (87.7)	3935161 (97.4)	< 0.001
Yes	117002 (2.8)	10903 (12.3)	106099 (2.6)
Chronic constipation
No	3943864 (95.5)	75459 (85.1)	3868405 (95.7)	< 0.001
Yes	186083 (4.5)	13228 (14.9)	172855 (4.3)
Mucus bloody stool
No	4088905 (99.0)	81690 (92.1)	4007215 (99.2)	< 0.001
Yes	41042 (1.0)	6997 (7.9)	34045 (0.8)
Chronic appendicitis/appendectomy
No	4052865 (98.1)	84350 (95.1)	3968515 (98.2)	< 0.001
Yes	77082 (1.9)	4337 (4.9)	72745 (1.8)
Chronic cholecystitis/cholecystectomy
No	4068649 (98.5)	85120 (96.0)	3983529 (98.6)	< 0.001
Yes	61298 (1.5)	3567 (4.0)	57731 (1.4)
Family history of CRC in FDR
No	21415 (0.5)	2168 (2.4)	19247 (0.5)	< 0.001
Yes	4096482 (99.2)	86291 (97.3)	4010191 (99.2)
Unknown	12050 (0.3)	228 (0.3)	11822 (0.3)

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