Test Characteristics at Increasing Calprotectin Cutoff Levels in the Referred Cohort Using the Imputed Data Set (n = 90)
| Test Characteristic | Fecal Calprotectin Cutoff | ||
|---|---|---|---|
| >50 μg/g | >100 μg/g | >250 μg/g | |
| Sensitivity (95% CI) | 0.99 (0.81–1.00) | 0.87 (0.65–0.96) | 0.81 (0.58–0.93) |
| Specificity (95% CI) | 0.84 (0.74–0.91) | 0.93 (0.84–0.97) | 0.98 (0.92–0.99) |
| PPV (95% CI) | 0.60 (0.42–0.76) | 0.74 (0.53–0.88) | 0.92 (0.69–0.98) |
| NPV (95% CI) | 1.00 (0.94–1.00) | 0.97 (0.89–0.99) | 0.96 (0.88–0.98) |
| Referrals avoided, No. (%)a | 61 (68) | 69 (77) | 74 (82) |
| Missed cases of IBD, No. (%)b | 0 (0) | 2 (12) | 3 (18) |
NPV = negative predictive value; PPV = positive predictive value; IBD = inflammatory bowel disease.
↵a Denominator is the 90 children in the referred cohort.
↵b Denominator is the 17 children in the referred cohort ultimately given a diagnosis of IBD.
Note: Pretest probability of IBD in this sample was 19%.