title: Faecal calprotectin for screening of patients with suspected inflammatory bowel disease: diagnostic meta-analysis.
abstract: OBJECTIVE
  To evaluate whether including a test for faecal calprotectin, a sensitive marker of intestinal inflammation, in the investigation of suspected inflammatory bowel disease reduces the number of unnecessary endoscopic procedures.
  
  
  METHODS
  Meta-analysis of diagnostic accuracy studies.
  
  
  METHODS
  Studies published in Medline and Embase up to October 2009. Interventions reviewed Measurement of faecal calprotectin level (index test) compared with endoscopy and histopathology of segmental biopsy samples (reference standard). Inclusion criteria Studies that had collected data prospectively in patients with suspected inflammatory bowel disease and allowed for construction of a two by two table. For each study, sensitivity and specificity of faecal calprotectin were analysed as bivariate data to account for a possible negative correlation within studies.
  
  
  RESULTS
  13 studies were included: six in adults (n=670), seven in children and teenagers (n=371). Inflammatory bowel disease was confirmed by endoscopy in 32% (n=215) of the adults and 61% (n=226) of the children and teenagers. In the studies of adults, the pooled sensitivity and pooled specificity of calprotectin was 0.93 (95% confidence interval 0.85 to 0.97) and 0.96 (0.79 to 0.99) and in the studies of children and teenagers was 0.92 (0.84 to 0.96) and 0.76 (0.62 to 0.86). The lower specificity in the studies of children and teenagers was significantly different from that in the studies of adults (P=0.048). Screening by measuring faecal calprotectin levels would result in a 67% reduction in the number of adults requiring endoscopy. Three of 33 adults who undergo endoscopy will not have inflammatory bowel disease but may have a different condition for which endoscopy is inevitable. The downside of this screening strategy is delayed diagnosis in 6% of adults because of a false negative test result. In the population of children and teenagers, 65 instead of 100 would undergo endoscopy. Nine of them will not have inflammatory bowel disease, and diagnosis will be delayed in 8% of the affected children.
  
  
  CONCLUSIONS
  Testing for faecal calprotectin is a useful screening tool for identifying patients who are most likely to need endoscopy for suspected inflammatory bowel disease. The discriminative power to safely exclude inflammatory bowel disease was significantly better in studies of adults than in studies of children.
authors.affiliation: Beatrix Children's Hospital, University Medical Center Groningen, PO Box 30001, 9700 RB Groningen, Netherlands. p.f.van.rheenen@bkk.umcg.nl
authors.forename: Patrick F
authors.initials: PF
authors.lastname: van Rheenen
authors.forename: Els
authors.initials: E
authors.lastname: Van de Vijver
authors.forename: Vaclav
authors.initials: V
authors.lastname: Fidler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D002648:Child; D016099:Endoscopy, Gastrointestinal; D005243:Feces / Q000737:chemistry*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis*; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D008875:Middle Aged; D012015:Reference Standards; D019564:Unnecessary Procedures; D055815:Young Adult
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex