title: Long-Term Prediction of the Demand of Colonoscopies Generated by a Population-Based Colorectal Cancer Screening Program.
abstract: OBJECTIVE
  To estimate the long-term need for colonoscopies after a positive fecal immunochemical test (FIT) and post-polypectomy surveillance in the context of a population-based colorectal cancer (CRC) screening program.
  
  
  METHODS
  A discrete-event simulation model was built to reproduce the process of CRC screening and post-polypectomy surveillance following European guidelines in a population of 100,000 men and women aged 50-69 years over a 20-year period. Screening consisted of biennial FIT and colonoscopy in participants with positive results. The model was mainly fed using data from the first and second rounds of a Spanish program (2010-2013). Data on post-polypectomy surveillance results were obtained from the literature. A probabilistic multivariate sensitivity analysis was performed on the effect of participation, FIT positivity, and adherence to surveillance colonoscopies. The main outcome variables were the number of colonoscopies after a positive FIT, surveillance colonoscopies, and the overall number of colonoscopies.
  
  
  RESULTS
  An average yearly number of 1,200 colonoscopies after a positive FIT were predicted per 100,000 inhabitants with a slight increase to 1,400 at the end of the 20-year period. Surveillance colonoscopies increased to an average of 1,000 per 100,000 inhabitants in the long-term, showing certain stabilization in the last years of the 20-year simulation horizon. The results were highly sensitive to FIT positivity.
  
  
  CONCLUSIONS
  Implementing a population-based CRC screening program will increase the demand for colonoscopies, which is expected to double in 20 years, mainly due to an increase in surveillance colonoscopies.
authors.affiliation: Epidemiology and Evaluation Department, Hospital del Mar, Barcelona, Spain.|IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.|Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Barcelona, Spain.
authors.forename: Mercè
authors.identifier: http://orcid.org/0000-0003-1926-2740
authors.initials: M
authors.lastname: Comas
authors.affiliation: CPS Market Access, Roche Diagnostics International Ltd., Rotkreuz, Switzerland.
authors.forename: Joan
authors.initials: J
authors.lastname: Mendivil
authors.affiliation: IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.|Gastroenterology Department, Hospital del Mar, Barcelona, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Andreu
authors.affiliation: Epidemiology and Evaluation Department, Hospital del Mar, Barcelona, Spain.|IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Hernández
authors.affiliation: Epidemiology and Evaluation Department, Hospital del Mar, Barcelona, Spain.|IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.|Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Castells
mesh_terms: D000368:Aged; D003113:Colonoscopy / Q000706:statistics & numerical data; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D055088:Early Detection of Cancer / Q000706:statistics & numerical data; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data; D008875:Middle Aged; D011155:Population Control / Q000706:statistics & numerical data; D011336:Probability