Fecal immunochemical test accuracy in average-risk colorectal cancer screening

Table 1 Performance characteristics of fecal immunochemical test-1 and -max for colorectal cancer detection at different positive thresholds n (%)

Hemoglobin concentration (ng/mL)	FIT strategy	Individuals with a positive result1	Sensitivity2	Specificity2	Positive predictive value2	Negative predictive value2	Positive likelihood ratio2	Negative likelihood ratio2
50	FIT13	67 (8.6)	100 (90-100)	92 (90-94)	7 (0-15)	100 (100-100)	12.48 (9.83-15.85)	-
	FITmax4	101 (13.0)	100 (90-100)	88.60 (85-90)	5 (0-10)	100 (100-100)	8.06 (6.69-9.72)	-
75	FIT13	61 (7.8)	100 (90-100)	93 (91-95)	8 (0-16)	100 (100-100)	13.82 (10.74-17)	-
	FITmax4	89 (11.4)	100 (90-100)	89 (87-91)	6 (0-11)	100 (100-100)	9.21 (7.53-11.28)	-
100	FIT13	55 (7.1)	100 (90-100)	94 (92-95)	9 (1-18)	100 (100-100)	15.48 (11.84-20.24)	-
	FITmax4	82 (10.5)	100 (90-100)	90 (88-92)	6 (0-12)	100 (100-100)	10.05 (8.13-12.43)	-
115	FIT13	51 (6.5)	100 (90-100)	94 (92-96)	10 (1-19)	100 (100-100)	16.83 (12.71-22.7)	-
	FITmax4	79 (10.1)	100 (90-100)	90 (88-93)	6 (0-12)	100 (100-100)	10.46 (8.42-12.99)	-
150	FIT13	48 (6.2)	80 (35-100)	94 (93-96)	8 (0-17)	100 (100-100)	14.07 (8.33-23.76)	0.21 (0.04-1.22)
	FITmax4	70 (9.0)	80 (35-100)	91 (89-94)	6 (0-12)	100 (100-100)	9.38 (5.72-15.40)	0.22 (0.04-1.26)
200	FIT13	45 (5.8)	80 (35-100)	95 (93-96)	9 (0-18)	100 (100-100)	15.10 (8.89-25.66)	0.21 (0.04-1.22)
	FITmax4	59 (7.6)	80 (35-100)	93 (91-95)	7 (0-14)	100 (100-100)	11.26 (6.78-18.69)	0.22 (0.04-1.24)

¹Values are expressed as absolute numbers and percentage;

²Values are expressed as percentage and its 95%CI;

³Fecal hemoglobin concentration in the first sample;

⁴Higher fecal hemoglobin concentration of the two samples. FIT: Fecal immunochemical test.

Table 2 Performance characteristics of fecal immunochemical test-1 and -max for advanced neoplasia¹ detection at different thresholds

Hemoglobin concentration (ng/mL)	FIT strategy	Individuals with a positive result2	Sensitivity3	P4	Specificity3	P5	Positive predictive value3	Negative predictive value3	Positive likelihood ratio3	Negative likelihood ratio3
50	FIT16	67 (8.6)	35 (25-45)	0.06	95 (93-97)	0.001	51 (38-63)	91 (89-93)	7.24 (4.72-11.13)	0.68 (0.59-0.79)
	FITmax7	101 (13.0)	42 (32-53)	0.03	91 (89-93)	< 0.001	41 (31-51)	92 (90-94)	4.98 (3.44-6.72)	0.63 (0.53-0.75)
75	FIT16	61 (7.8)	33 (23-43)	0.2	96 (94-97)	0.01	52 (39-66)	91 (89-93)	7.76 (4.92-12.23)	0.70 (0.61-081)
	FITmax7	89 (11.4)	40 (30-51)	0.1	93 (91-95)	0.03	44 (33-55)	92 (89-94)	5.48 (3.82-7.87)	0.65 (0.55-0.76)
100	FIT16	55 (7.1)	32 (22-42)	0.5	96 (95-98)	0.5	56 (42-70)	91 (89-93)	9.08 (5.57-14.80)	0.71 (0.61-0.81)
	FITmax7	82 (10.5)	37 (27-47)	1	93 (91-95)	0.5	44 (33-55)	91 (89-93)	5.50 (3.76-8.05)	0.67 (0.58-0.79)
115	FIT16	51 (6.5)	30 (20-40)		97 (95-98)		57 (42-71)	91 (88-93)	9.27 (5.56-15.46)	0.72 (0.64-0.83)
	FITmax7	79 (10.1)	36 (26-46)		94 (92-95)		44 (33-56)	91 (89-93)	5.59 (3.79-8.26)	0.68 (0.59-0.79)
150	FIT16	48 (6.2)	28 (18-37)	0.5	97 (96-98)	1	56 (41-71)	90 (88-93)	9.04 (5.33-15.34)	0.74 (0.66-0.84)
	FITmax7	70 (9.0)	32 (22-42)	0.1	94 (92-96)	0.06	44 (32-57)	91 (88-93)	5.59 (3.67-8.51)	0.72 (0.63-0.83)
200	FIT16	45 (5.8)	28 (18-37)	0.5	97 (96-99)	0.1	60 (44-75)	90 (88-93)	10.55 (6.04-18.41)	0.74 (0.65-0.84)
	FITmax7	59 (7.6)	28 (18-37)	0.08	95 (94-97)	< 0.001	46 (32-59)	90 (88-93)	5.93 (3.72-9.45)	0.76 (0.67-0.86)

¹Advanced neoplasia: advanced adenomas (adenoma > 1 cm in size, with high-grade dysplasia, or with villous component > 25) or colorectal cancer;

²Values are expressed as absolute numbers and percentage;

³Values are expressed as percentage and its 95%CI; ⁴Significance of the sensitivity differences when compared with the optimal cut-off point in McNemar test. Differences with P < 0.05 are considered statistically significant; ⁵Significance of the specificity differences when compared with the optimal cut-off point in McNemar test. Differences with P < 0.05 are considered statistically significant;

⁶Fecal hemoglobin concentration in the first sample;

⁷Higher fecal hemoglobin concentration of the two samples. FIT: Fecal immunochemical test.

Table 3 Number of colonoscopies needed to detect one lesion and cost per lesion (€) according to positivity threshold and fecal immunochemical test testing strategy

Lesion	Positivity threshold (ng/mL)	No. need to scope		Cost per lesion detected (€)		Cost increment (€)
		FIT1	FITmax	FIT1	FITmax
CRC	0	155.80		16898
	50	13.40	20.20	2206	3489	58.16
	75	12.20	17.80	2038	3223	58.15
	100	11.00	16.40	1912	3055	59.78
	115	10.20	15.80	1814	2985	64.55
	150	12.00	17.50	2163	3451	59.55
	200	11.25	14.75	2075	3083	48.58
Advanced neoplasia1	0	8.20		889
	50	1.97	2.46	317	425	34.07
	75	1.91	2.28	312	413	32.37
	100	1.77	2.28	302	424	40.40
	115	1.76	2.26	306	426	39.22
	150	1.78	2.26	312	445	42.63
	200	1.67	2.19	311	456	46.62

¹Advanced neoplasia: advanced adenomas (adenoma > 1 cm in size with high-grade dysplasia or with villous component > 25) or colorectal cancer. FIT: Fecal immunochemical test; CRC: Colorectal cancer.