title: Cost-effectiveness analysis of 3-D computerized tomography colonography versus optical colonoscopy for imaging symptomatic gastroenterology patients.
abstract: BACKGROUND
  When symptomatic gastroenterology patients have an indication for colonic imaging, clinicians have a choice between optical colonoscopy (OC) and computerized tomography colonography with three-dimensional reconstruction (3-D CTC). 3-D CTC provides a minimally invasive and rapid evaluation of the entire colon, and it can be an efficient modality for diagnosing symptoms. It allows for a more targeted use of OC, which is associated with a higher risk of major adverse events and higher procedural costs. A case can be made for 3-D CTC as a primary test for colonic imaging followed if necessary by targeted therapeutic OC; however, the relative long-term costs and benefits of introducing 3-D CTC as a first-line investigation are unknown.
  
  
  OBJECTIVE
  The aim of this study was to assess the cost effectiveness of 3-D CTC versus OC for colonic imaging of symptomatic gastroenterology patients in the UK NHS.
  
  
  METHODS
  We used a Markov model to follow a cohort of 100,000 symptomatic gastroenterology patients, aged 50 years or older, and estimate the expected lifetime outcomes, life years (LYs) and quality-adjusted life years (QALYs), and costs (£, 2010-2011) associated with 3-D CTC and OC. Sensitivity analyses were performed to assess the robustness of the base-case cost-effectiveness results to variation in input parameters and methodological assumptions.
  
  
  RESULTS
  3D-CTC provided a similar number of LYs (7.737 vs 7.739) and QALYs (7.013 vs 7.018) per individual compared with OC, and it was associated with substantially lower mean costs per patient (£467 vs £583), leading to a positive incremental net benefit. After accounting for the overall uncertainty, the probability of 3-D CTC being cost effective was around 60 %, at typical willingness-to-pay values of £20,000-£30,000 per QALY gained.
  
  
  CONCLUSIONS
  3-D CTC is a cost-saving and cost-effective option for colonic imaging of symptomatic gastroenterology patients compared with OC.
authors.affiliation: Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, 15-17 Tavistock Place, London WC1H 9SH, UK. manuel.gomes@lshtm.ac.uk
authors.forename: Manuel
authors.initials: M
authors.lastname: Gomes
authors.forename: Robert W
authors.initials: RW
authors.lastname: Aldridge
authors.forename: Peter
authors.initials: P
authors.lastname: Wylie
authors.forename: James
authors.initials: J
authors.lastname: Bell
authors.forename: Owen
authors.initials: O
authors.lastname: Epstein
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D023881:Colonography, Computed Tomographic / Q000191:economics*; D003113:Colonoscopy / Q000191:economics*; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D015233:Models, Statistical; D017063:Outcome Assessment, Health Care; D019057:Quality-Adjusted Life Years; D013222:State Medicine / Q000191:economics*; D006113:United Kingdom