title: Optimal resource allocation in colonoscopy: timing of follow-up colonoscopies in relation to adenoma detection rates.
abstract: OBJECTIVE
  The assessment of indications for follow-up colonoscopy may help to improve the allocation of available endoscopy resources. The aim of this study was to assess the timing of early follow-up colonoscopy and surveillance utilization in relation to adenoma detection rate (ADR) at follow-up.
  
  
  METHODS
  An assessment of the timing and yield of follow-up colonoscopies was performed in patients with non-inflammatory bowel disease (IBD) in a Dutch multicenter study. The primary outcome was the number of patients with a prior (index) colonoscopy. The necessity for follow-up procedures was assessed using the ADR.
  
  
  RESULTS
  Of 4800 consecutive patients undergoing a colonoscopy, 1249 non-IBD patients had undergone an index colonoscopy. Of these, follow-up procedures were performed within 1 year in 27 % (331/1249). Excluding incomplete colonoscopy, incomplete polypectomy, or poor bowel preparation on index, the ADR on early follow-up was 4 % for symptomatic and 26 % for asymptomatic patients. Among the asymptomatic patients with a follow-up colonoscopy at > 1 year (n = 463), an ADR of 23 % (108/463) was found. In 27 % of these patients, the observed surveillance intervals were in accordance with American Gastroenterological Association (AGA) surveillance recommendations; 60 % were classified as over-utilization and 13 % as under-utilization according to the AGA. Optimal utilization follow-up colonoscopies had higher ADRs on follow-up compared with over-utilized procedures (31 % vs. 17 %; P < 0.001).
  
  
  CONCLUSIONS
  Follow-up colonoscopy in symptomatic patients within a year has limited value in terms of adenoma detection. A considerable proportion of surveillance colonoscopies are performed too early according to current guidelines, resulting in low detection rates. Both aspects can be targeted for optimal usage in endoscopic capacity.
authors.affiliation: Departments of Gastroenterology and Hepatology of Erasmus MC University Medical Center, Rotterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Sint Nicolaas
authors.forename: V
authors.initials: V
authors.lastname: de Jonge
authors.forename: O
authors.initials: O
authors.lastname: van Baalen
authors.forename: F J G M
authors.initials: FJ
authors.lastname: Kubben
authors.forename: W
authors.initials: W
authors.lastname: Moolenaar
authors.forename: M F J
authors.initials: MF
authors.lastname: Stolk
authors.forename: E J
authors.initials: EJ
authors.lastname: Kuipers
authors.forename: M E
authors.initials: ME
authors.lastname: van Leerdam
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000368:Aged; D058070:Asymptomatic Diseases; D003113:Colonoscopy / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D017410:Practice Guidelines as Topic; D040841:Resource Allocation / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013997:Time Factors