title: Application of a conversion factor to estimate the adenoma detection rate from the polyp detection rate.
abstract: BACKGROUND
  The adenoma detection rate (ADR) is a quality benchmark for colonoscopy. Many practices find it difficult to determine the ADR because it requires a combination of endoscopic and histologic findings. It may be possible to apply a conversion factor to estimate the ADR from the polyp detection rate (PDR).
  
  
  OBJECTIVE
  To create a conversion factor that can be used to accurately estimate the ADR from the PDR.
  
  
  METHODS
  This was a retrospective study of colonoscopies performed by board-certified gastroenterologists to determine the average adenoma to polyp detection rate quotient (APDRQ) for all endoscopists, individually and as a group.
  
  
  METHODS
  Academic group practice.
  
  
  METHODS
  The group average APDRQ was used as a conversion factor for the endoscopist's PDR to estimate the ADR.
  
  
  METHODS
  The strength of the relationship between the estimated ADR and the actual ADR determined by Pearson's correlation coefficient.
  
  
  RESULTS
  A total of 3367 colonoscopies performed by 20 staff gastroenterologists were included. The average ADR for all indications, all patient age groups, and both sexes was 0.17 (range 0.09-0.27, standard deviation 0.05). The average APDRQ was 0.64 (range 0.46-1.00, standard deviation 0.13). The correlation between the estimated ADR and the actual ADR was 0.85 (95% CI, 0.65-0.93, P = .000001).
  
  
  CONCLUSIONS
  Retrospective study in 1 practice setting with all patient types.
  
  
  CONCLUSIONS
  The use of a conversion factor can accurately estimate the ADR from the PDR. Further study is needed to determine whether such a conversion factor can be applied to different practice settings and patient groups.
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Dawn L
authors.initials: DL
authors.lastname: Francis
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Rodriguez-Correa
authors.forename: Anna
authors.initials: A
authors.lastname: Buchner
authors.forename: Gavin C
authors.initials: GC
authors.lastname: Harewood
authors.forename: Michael
authors.initials: M
authors.lastname: Wallace
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000465:Algorithms; D003111:Colonic Polyps / Q000175:diagnosis*; D003113:Colonoscopy / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013223:Statistics as Topic / Q000379:methods