Assessment of disease activity by fecal immunochemical test in ulcerative colitis

Table 1 Characteristics of enrolled cases

Characteristics variables	Value
Age (yr), mean (range) ± SD	47.9 (22-75) ± 12.5
Male/Female, n (%)	60/22 (73.2/26.8)
Disease duration (mo), mean (range) ± SD	33.5 (0-217) ± 48.3
MES, n (%)
0	21 (25.6)
1	39 (47.6)
2	15 (18.3)
3	7 (8.5)
Disease extent, n (%)
Extensive colitis	32 (39.0)
Left sided colitis	30 (36.6)
Proctitis	20 (24.4)
Fecal hemoglobin concentrations (ng/mL), n (%)
0-7, negative	47 (57.3)
7-100	21 (25.6)
100-1000	11 (13.4)
> 1000	3 (3.7)
Drug at study entry, n (%)
Oral / Suppository 5-ASA	64 (100.0)/18 (22.0)
Systemic steroids	17 (20.7)
Azathioprine	23 (28.0)
Anti-TNFα	6 (7.3)

MES: Mayo endoscopic subscore; 5-ASA: 5-aminosalicylic acids; TNF: Tumor necrosis factor.

Table 2 Negative fecal immunochemical test probability (%) and mean fecal immunochemical test values according to mayo endoscopic subscore

MES	Negative FIT (%)	mean FIT (ng/mL)
0	21/21 (100)	0
1	44/60 (73.3)	33.94
2 or 3	4/22 (18.2)	> 134.891

¹Three cases in MES “2” or “3” were measured more than 1000 ng/mL fecal hemoglobin concentration. MES: Mayo endoscopic subscore; FIT: Fecal immunochemical test.

Table 3 Mayo endoscopic subscore according to fecal immunochemical test values

	n (%)
Negative FIT cases (n = 47)
MES 0 or 1	43 (91.5)
MES 2 or 3	4 (8.5)
Positive FIT cases (n = 35)
MES 0	0
MES 1	17 (48.6)
MES 2 or 3	18 (51.4)

MES: Mayo endoscopic subscore; FIT: Fecal immunochemical test.

Table 4 Sensitivity, specificity and predictive value of fecal immunochemical test for mucosal healing (mayo endoscopic subscore 0 or 1)

	Negative FIT (< 7 ng/mL)
Sensitivity (95%CI)	0.73 (0.60-0.83)
Specificity (95%CI)	0.81 (0.59-0.94)
PPV (95%CI)	0.91 (0.80-0.97)
NPV (95%CI)	0.52 (0.35-0.70)
Accuracy (95%CI)	0.73 (0.62-0.82)

MES: Mayo endoscopic subscore; FIT: Fecal immunochemical test; PPV: Positive predictive value; NPV: Negative predictive value.

Table 5 Sensitivity, specificity and predictive value of fecal immunochemical test for endoscopic active disease (mayo endoscopic subscore 2 or 3)

	Positive FIT (> 100 ng/mL)
Sensitivity (95%CI)	0.45 (0.24-0.67)
Specificity (95%CI)	0.93 (0.83-0.98)
PPV (95%CI)	0.71 (0.41-0.91)
NPV (95%CI)	0.82 (0.71-0.90)
Accuracy (95%CI)	0.26 (0.17-0.37)

MES: Mayo endoscopic subscore; FIT: Fecal immunochemical test; PPV: Positive predictive value; NPV: Negative predictive value.

Table 6 Negative fecal immunochemical test probability (%) and mean fecal immunochemical test values according to clinical condition

Clinical condition	Negative FIT (%)	mean FIT (ng/mL)
Remission status (n = 38)	31/38 (81.6)	6.12
Active status (n = 44)	16/44 (36.4)	> 167.41

¹Three cases in clinical active were measured more than 1000 ng/mL fecal hemoglobin concentration. FIT: Fecal immunochemical test.

Table 7 Mayo endoscopic subscore according to clinical condition

Clinical condition	n (%)
Remission status (n = 38)
MES 0 or 1	37 (97.4)
MES 2	1 (2.6)
MES 3	0
Active status (n = 44)
MES 0 or 1	23 (52.3)
MES 2	14 (31.8)
MES 3	7 (15.9)

MES: Mayo endoscopic subscore.