. 2019 Feb 15;29(1):010707. doi: 10.11613/BM.2019.010707

Table 2. Between-method variability for measuring faecal calprotectin with respect to the extraction method used and stool consistency.

			Hard Stool		Normal Stool		Liquid Stool
	FC concentration mg/kg	P*	FC concentration, mg/kg	Mean bias,%	FC concentration, mg/kg	Mean bias,%	FC concentration, mg/kg	Mean bias,%	P^†
Weighing method comparison, N = 52
EliA™ Calprotectin	104.0 (36.0 - 415.0)	0.025	84.8 (22.0 - 257.5)	87.9 (N = 8)	74.0 (26.0 - 217.5)	38.1 (N = 29)	162.0 (58.5 - 1045.5)	- 8.4 (N = 15)	0.005 (1)/ (2)/ (3)
Bühlmann fCAL® Turbo	160.5 (59.5 - 611.0)	0.025	491.5 (127.0 - 611.0)	87.9 (N = 8)	124.0 (57.8 - 373.5)	38.1 (N = 29)	152.0 (66.5 - 929.3)	- 8.4 (N = 15)	0.005 (1)/ (2)/ (3)
EliA Stool Extraction Kit vs Calex^® Cap “N”, N = 77
EliA™ Calprotectin	91.0 (38.1 - 453.5)	< 0.001	27.0 (19.3 - 61.3)	89.2 (N = 11)	77.0 (32.3 - 390.0)	64.1 (N = 47)	277.0 (88.8 - 924.3)	8.1 (N = 19)	< 0.001 (3)/ (1) (2)
Bühlmann fCAL® Turbo	190.5 (76.3 - 710.9)	< 0.001	103.5 (41.1 - 594.1)	89.2 (N = 11)	249.0 (74.8 - 555.9)	64.1 (N = 47)	203.5 (95.8 - 999.1)	8.1 (N = 19)	< 0.001 (3)/ (1) (2)
FC - faecal calprotectin concentration is presented as median (interquartile range). Wilcoxon test. Stool classes are presented according to Bristol stool scale (BSS): hard (BSS 1, 2), normal (BSS 3, 4, 5) and liquid (BSS 6, 7). ^†Kruskal-Wallis test with Conover post-hoc* pairwise comparison. Mean bias - mean of calculated biases (Bias = [(FC_{fCAL Turbo} – FC_EliA) / ((FC_{fCAL Turbo}+FC_EliA)/2)] x 100). P < 0.05 was considered statistically significant. The allowable bias was set at 22.6%. (1)/ (2)/ (3) - respective biases differ significantly between 3 classes according to stool consistency; (3)/ (1) (2) - bias obtained for class 3 is significantly different from respective biases obtained for classes 1 and 2 according to stool consistency.