title: Narrow band imaging versus conventional white light colonoscopy for the detection of colorectal polyps.
abstract: BACKGROUND
  It has been suggested that narrow band imaging colonoscopy (NBI) might be better for detection of colorectal polyps than white light colonoscopy (WLC).
  
  
  OBJECTIVE
  To compare standard or high definition white light colonoscopy with narrow band imaging colonoscopy for detection of colorectal polyps.
  
  
  METHODS
  We searched The Cochrane Library, MEDLINE, and EMBASE to August 2011. We scanned bibliographies of relevant publications and wrote to experts for additional trials.
  
  
  METHODS
  Two authors (NA and GB) independently applied the inclusion criteria and extracted the data to all potential studies without blinding.
  
  
  METHODS
  Authors extracted data independently. Trials with adequate randomisation, allocation concealment, and complete outcome data reporting, as well as without selective outcome reporting or other bias were classified as having a lowest risk of bias. Random-effects and fixed-effect meta-analyses were conducted.
  
  
  RESULTS
  We identified 11 randomised trials comparing WLC with NBI for detection of colorectal polyps. In total eight randomised trials with 3673 participants provided data for our analyses. There was no statistically significant difference between WLC (standard definition and high definition pooled) and NBI for the detection of patients with colorectal polyps (6 trials, n = 2832, RR 0.97, 95% CI 0.91 to 1.04), patients with colorectal adenomas (8 trials, n = 3673, RR 0.94, 95% CI 0.87 to 1.02), or patients with colorectal hyperplastic polyps (2 trials, n = 645, RR 0.87, 95% CI 0.76 to 1.00). Number of patients with at least one colorectal adenoma was not significantly different between WLC and NBI group irrespective of adenoma size (< 5 mm:RR 0.95, 95% CI 0.84 to 1.08, I(2) = 56%; 6 to 9 mm: RR 1.06, 95% CI 0.81 to 1.39, I(2) = 0%; ≥ 10 mm: RR 1.06, 95% CI 0.77 to 1.45, I(2) = 0%). Number of patients with at least one colorectal polyp, or colorectal adenoma was significantly lower in the standard definition WLC group compared to NBI group in fixed-effect meta-analysis (RR 0.87, 95% CI 0.78 to 0.97, I(2) = 78%; RR 0.87, 95% CI 0.77 to 0.99, I(2) = 0%, respectively), but not significantly different in random-effects meta-analysis (RR 0.86, 95% CI 0.68 to 1.10, I(2) = 78%). There was no statistically significant difference between high definition WLC and NBI in the number of patiens with at least one colorectal polyp or colorectal adenoma (RR 1.10, 95% CI 0.95 to 1.28; RR 0.87, 95% CI 0.77 to 0.99, I(2) = 0%, respectively).
  
  
  CONCLUSIONS
  We could not find convincing evidence that NBI is significantly better than high definition WLC for the detection of patients with colorectal polyps, or colorectal adenomas. We found evidence that NBI might be better than standard definition WLC and equal to high definition WLC for detection the patients with colorectal polyps, or colorectal adenomas.
authors.affiliation: Department of Internal Medicine - Gastroenterology and Hepatology, Medical Faculty, University of Nis, Nis, Serbia. nagornia@gmail.com.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Nagorni
authors.forename: Goran
authors.initials: G
authors.lastname: Bjelakovic
authors.forename: Bratislav
authors.initials: B
authors.lastname: Petrovic
mesh_terms: D003111:Colonic Polyps / Q000175:diagnosis*; D020685:Colonoscopes; D003113:Colonoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007417:Intestinal Polyps / Q000175:diagnosis*; D008027:Light; D008029:Lighting / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D012002:Rectal Diseases / Q000175:diagnosis*