Achieving high quality colonoscopy: using graphical representation to measure performance and reset standards

Colorectal Dis. 2012 Dec;14(12):1538-45. doi: 10.1111/j.1463-1318.2012.03057.x.


Aim: Completeness and thoroughness of colonoscopy are measured by the caecal intubation rate (CIR) and the adenoma detection rate (ADR). National standards are ≥ 90% and ≥ 10% respectively. Variability in CIR and ADR have been demonstrated but comparison between individuals and units is difficult. We aimed to assess the performance of colonoscopy in endoscopy units in the northeast of England.

Method: Data on colonoscopy performance and sedation use were collected over 3 months from 12 units. Colonoscopies performed by screening colonoscopists were included for the CIR only. Funnel plots with upper and lower 95% confidence limits for CIR and ADR were created.

Results: CIR was 92.5% (n = 5720) and ADR 15.9% (n = 4748). All units and 128 (99.2%) colonoscopists were above the lower limit for CIR. All units achieved the ADR standard with 10 above the upper limit. Ninety-nine (76.7%) colonoscopists were above 10%, 16 (12.4%) above the upper limit and 7 (5.4%) below the lower limit. Median medication doses were 2.2 mg midazolam, 29.4 mg pethidine and 83.3 μg fentanyl. In all, 15.1% of colonoscopies were unsedated. Complications were bleeding (0.10%) and perforation (0.02%). There was one death possibly related to bowel preparation.

Conclusion: Results indicate that colonoscopies are performed safely and to a high standard. Funnel plots can highlight variability and areas for improvement. Analyses of ADR presented graphically around the global mean suggest that the national standard should be reset at 15%.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / diagnosis*
  • Catheterization / standards*
  • Cecum
  • Clinical Competence
  • Colonic Neoplasms / diagnosis*
  • Colonoscopy / adverse effects
  • Colonoscopy / standards*
  • Colonoscopy / statistics & numerical data
  • Deep Sedation / statistics & numerical data*
  • England
  • Fentanyl
  • Humans
  • Hypnotics and Sedatives / administration & dosage
  • Meperidine
  • Midazolam
  • Narcotics / administration & dosage
  • Practice Guidelines as Topic
  • Quality Assurance, Health Care / methods*
  • Quality Improvement


  • Hypnotics and Sedatives
  • Narcotics
  • Meperidine
  • Midazolam
  • Fentanyl