High-risk symptoms and quantitative faecal immunochemical test accuracy: Systematic review and meta-analysis

Table 3 Colorectal cancer detection: Diagnostic accuracy parameters based on quantitative faecal immunochemical test for haemoglobin threshold concentration and brand (DerSimonian´s method)"

Variable	Studies (n)	Sensitivity1	I22	Specificity1	I22	Positive LR3	I22	Negative LR3	I22	Diagnostic OR3	I22	Pa
OC-Sensor, > LoD µg Hb/g faeces
All studies	4	98.2 (96.2-99.3)	0.0	35.8 (34.2-37.3)	96.1	1.55 (1.37-1.75)	94.2	0.07 (0.03-0.14)	0.0	21.41 (10.07-45.5)	0.0		0.6
OC-Sensor, ≥ 10 µg Hb/g faeces
All studies	8	90.8 (87.9-93.2)	69.7	79.9 (79.1-80.7)	99.4	4.79 (2.96-7.76)	99.1	0.15 (0.09-0.23)	52.7	31.44 (19.50-50.68)	44.7		0.09
100% Symptomatic	4	94.4 (91.4-96.6)	0.0	65.9 (64.4-67.4)	99.3	2.97 (1.78-4.95)	99.0	0.10 (0.06-0.15)	0.0	28.49 (17.77-45.67)	0.0		0.6
Mixed patients	4	83.2 (76.5-88.6)	44.5	88.2 (87.4-89.0)	96.7	7.78 (4.72-12.82)	95.1	0.21 (0.13-0.33)	30.7	35.36 (14.19-88.10)	71.0		0.6
CRC prevalence ≥ 2.5%	5	91.9 (88.7-94.3)	76.0	69.7 (68.5-71.0)	99.2	3.16 (1.99-5.0)	98.8	0.13 (0.07-0.25)	66.5	23.20 (14.76-36.47)	20.0		0.2
CRC prevalence < 2.5%	3	86.3 (77.7-92.5)	48.0	90.2 (89.4-91.1)	72.6	9.21 (7.23-11.74)	55.1	0.17 (0.09-0.33)	26.4	52.33 (27.23-100.58)	10.0		0.7
OC-Sensor, ≥ 15 µg Hb/g faeces
All studies	5	91.0 (87.8-93.6)	73.3	81.8 (80.9-82.7)	99.7	4.77 (2.34-9.71)	99.4	0.15 (0.09-0.25)	57.3	36.64 (20.43-65.71)	49.7		0.04
100% Symptomatic4	3	93.6 (90.2-96.0)	32.6	65.8 (64.1-67.5)	99.5	2.91 (1.46-5.78)	99.3	0.11 (0.07-0.16)	0.0	29.10 (12.74-66.46)	35.5		0.67
OC-Sensor, ≥ 20 µg Hb/g faeces
All studies	5	90.3 (86.9-93.0)	75.6(86.9-93.0)	83.4 (82.5-84.2)	99.7	5.30 (2.47-11.34)	99.4	0.15 (0.09-0.27)	67.2	39.02 (21.48-70.88)	56.1		0.04
100% Symptomatic4	3	92.9 (89.5-95.5)	26.1	68.0 (66.3-69.7)	99.5	3.14 (1.52-6.50)	99.3	0.11 (0.07-0.17)	0.0	29.81 (15.05-59.04)	29.2		0.67

¹Values are expressed as percentages and its 95% confidence interval;

²Values are expressed as percentages;

³Values are expressed as absolute numbers and its 95% confidence interval;

⁴The studies that comprise the 100% symptomatic subgroup also have colorectal cancer prevalence ≥ 2.5%; P^a: Significance of the threshold effect using the Spearman rank correlation (P < 0.01 is considered statistically significant). I²: Inconsistency index; LoD: Limit of detection; LR: Likelihood ratio; OR: Odds ratio; CRC: Colorectal cancer.