Table 2: Q1. In adults with moderate-severe UC achieving resolution of rectal bleeding after induction therapy with a biologic or tofacitinib, how accurate is a fecal calprotectin cut-off of 50 for ruling out moderate to severe endoscopically active disease (Mayo endoscopy score 2/3), obviating the need for routine endoscopic assessment?
Population/Setting: Adults with moderate-severe UC who have resolution of rectal bleeding after biologic or tofacitinib induction therapy – low pre-test probability/likelihood of having moderate to severe endoscopically active disease (patients with rectal bleeding score 0 + stool frequency score 0/1) with observed prevalence of moderate to severe endoscopically active disease (Mayo endoscopy score 2/3) of 25%; Intermediate pre-test probability/likelihood of having endoscopically active disease (patients with rectal bleeding score 0 + stool frequency score 2 or 3) with observed prevalence of moderate to severe active endoscopically active disease (Mayo endoscopy score 2/3) of 65% Pooled sensitivity fecal calprotectin with cut-off ≤50 (±10)μg/g: 0.82 (95% CI: 0.74 to 0.89) | Pooled specificity fecal calprotectin with cut-off ≤50 (±10)μg/g: 0.74 (95% CI: 0.65 to 0.82). Reference Test: Lower endoscopy, locally read
| Test result | Number of results per 1000 patients tested (95% CI) | Number of studies, participants | Quality of the Evidence (GRADE) | Comments | |
|---|---|---|---|---|---|
| Low-likelihood (Prevalence 25%) | Intermediate-likelihood (Prevalence 65%) | ||||
| True positives (patients with moderate to severe endoscopically active disease) | 205 (185 to 223) | 533 (481 to 579) | 14 studies, 1658 patients | ⊕⊕⊕○ MODERATE1 (Inconsistency) | TP may lead to diagnostic endoscopy for confirmation and modification/optimization of therapy (if FC used as triage strategy), potentially reducing risk of disease-related complications. TP will have further testing (lower endoscopy) and/or intervention which may lead to side effects. |
| False negatives (patients incorrectly classified as being in endoscopic remission or having mildly active disease) | 45 (27 to 65) | 117 (71 to 169) | FN may lead to inadequate treatment and potentially increased risk of disease-related complications due to delay in detection of moderate to severe endoscopically active disease | ||
| True negatives (patients in endoscopic remission or having mildly active disease) | 555 (488 to 615) | 259 (227 to 287) | TN will likely be reassured, avoid an invasive test but may still be retested with fecal calprotectin periodically | ||
| False positives (patients incorrectly classified as having moderate to severe endoscopically active disease) | 195 (135 to 262) | 91 (63 to 123) | FP will likely have further testing (if fecal calprotectin is used as triage strategy) or may be over-treated (if fecal calprotecin is used a test replacement strategy) and will increase anxiety, complications and resource use. | ||
High unexplained heterogeneity, selective inclusion of studies corresponding to cut-off of ≤50 (±10) μg/g.