Noninvasive Tests for Inflammatory Bowel Disease: A Meta-analysis

BACKGROUND: The clinical presentation of pediatric inflammatory bowel disease (IBD) is often nonspecific and overlaps with functional gastrointestinal disorders. OBJECTIVE: To determine the diagnostic accuracy of symptoms, signs, noninvasive tests, and test combinations that can assist the clinician with the diagnosis of IBD in symptomatic children. METHODS: A literature search was conducted of Medline and Embase. Two reviewers independently selected studies reporting on the diagnostic accuracy of tests for IBD, with confirmation by endoscopy and histopathology or clinical follow-up, in children with chronic gastrointestinal symptoms. Two reviewers independently extracted data and assessed study quality with the QUADAS-2, an evidence-based quality assessment tool for diagnostic accuracy studies. RESULTS: Nineteen studies were included (N = 2806). Symptoms (abdominal pain, diarrhea, rectal bleeding, and weight loss) had pooled sensitivities ranging from 0.48 to 0.82 and specificities ranging from 0.17 to 0.78. Of all the blood markers, C-reactive protein (CRP) (9 studies) and albumin (6 studies) had the best performance, with pooled sensitivities of 0.63 (0.51-0.73) and 0.48 (0.31-0.66), respectively, and specificities of 0.88 (0.80-0.93) and 0.94 (0.86-0.98). Assessment of fecal calprotectin (FCal) (10 studies) had a pooled sensitivity of 0.99 (0.92-1.00) and a specificity of 0.65 (0.54-0.74). One limitation was that none of the studies was conducted in nonreferred children. CONCLUSIONS: In children whose pediatrician is considering an endoscopy, symptoms are not accurate enough to identify low-risk patients in whom an endoscopy can be avoided. FCal, CRP, and albumin findings are potentially of clinical value, given their ability to select children at low risk (negative FCal test result) or high risk (positive CRP or albumin test result) for IBD.