Table 3.

Diagnostic accuracy of fecal calprotectin at different thresholds

PPV: positive predictive value; NPV: negative predictive value; PLR: positive likelihood ratio;

CI: confidence interval.

Threshold fecal calprotectin (μg/g)	Sensitivity (95% CI)		Specificity (95% CI)		PPV (95% CI)		NPV (95% CI)		PLR (95% CI)
A: Inflammatory bowel disease (IBD) or abnormal GI tract vs. functional disease
20	0.89	(0.83–0.93)	0.49	(0.44–0.53)	0.32	(0.28–0.37)	0.94	(0.91–0.96)	1.73	(1.57–1.91)
50	0.79	(0.71–0.85)	0.74	(0.70–0.77)	0.45	(0.39–0.52)	0.93	(0.90–0.95)	3.02	(2.57–3.54)
70	0.73	(0.65–0.80)	0.80	(0.76–0.83)	0.50	(0.44–0.57)	0.92	(0.89–0.94)	3.66	(3.03–4.43)
100	0.70	(0.62–0.77)	0.87	(0.84–0.90)	0.60	(0.52–0.67)	0.91	(0.89–0.93)	5.42	(4.27–6.87)
B: IBD vs. functional disease
20	0.99	(0.93–1.00)	0.49	(0.44–0.53)	0.24	(0.20–0.28)	1.00	(0.98–1.00)	1.92	(1.77–2.09)
50	0.97	(0.90–0.99)	0.74	(0.70–0.77)	0.37	(0.31–0.44)	0.99	(0.98–1.00)	3.70	(3.20–4.27)
70	0.97	(0.90–0.99)	0.80	(0.76–0.83)	0.44	(0.37–0.51)	0.99	(0.98–1.00)	4.84	(4.09–5.74)
100	0.96	(0.89–0.99)	0.87	(0.84–0.90)	0.54	(0.46–0.62)	0.99	(0.98–1.00)	7.41	(5.96–9.22)