title: Health benefits and cost-effectiveness of a hybrid screening strategy for colorectal cancer.
abstract: OBJECTIVE
  Colorectal cancer (CRC) screening guidelines recommend screening schedules for each single type of test except for concurrent sigmoidoscopy and fecal occult blood test (FOBT). We investigated the cost-effectiveness of a hybrid screening strategy that was based on a fecal immunological test (FIT) and colonoscopy.
  
  
  METHODS
  We conducted a cost-effectiveness analysis by using the Archimedes Model to evaluate the effects of different CRC screening strategies on health outcomes and costs related to CRC in a population that represents members of Kaiser Permanente Northern California. The Archimedes Model is a large-scale simulation of human physiology, diseases, interventions, and health care systems. The CRC submodel in the Archimedes Model was derived from public databases, published epidemiologic studies, and clinical trials.
  
  
  RESULTS
  A hybrid screening strategy led to substantial reductions in CRC incidence and mortality, gains in quality-adjusted life years (QALYs), and reductions in costs, comparable with those of the best single-test strategies. Screening by annual FIT of patients 50-65 years old and then a single colonoscopy when they were 66 years old (FIT/COLOx1) reduced CRC incidence by 72% and gained 110 QALYs for every 1000 people during a period of 30 years, compared with no screening. Compared with annual FIT, FIT/COLOx1 gained 1400 QALYs/100,000 persons at an incremental cost of $9700/QALY gained and required 55% fewer FITs. Compared with FIT/COLOx1, colonoscopy at 10-year intervals gained 500 QALYs/100,000 at an incremental cost of $35,100/QALY gained but required 37% more colonoscopies. Over the ranges of parameters examined, the cost-effectiveness of hybrid screening strategies was slightly more sensitive to the adherence rate with colonoscopy than the adherence rate with yearly FIT. Uncertainties associated with estimates of FIT performance within a program setting and sensitivities for flat and right-sided lesions are expected to have significant impacts on the cost-effectiveness results.
  
  
  CONCLUSIONS
  In our simulation model, a strategy of annual or biennial FIT, beginning when patients are 50 years old, with a single colonoscopy when they are 66 years old, delivers clinical and economic outcomes similar to those of CRC screening by single-modality strategies, with a favorable impact on resources demand.
authors.affiliation: Archimedes Inc, San Francisco, California 94105, USA. tuan.dinh@archimedesmodel.com
authors.forename: Tuan
authors.initials: T
authors.lastname: Dinh
authors.forename: Uri
authors.initials: U
authors.lastname: Ladabaum
authors.forename: Peter
authors.initials: P
authors.lastname: Alperin
authors.forename: Cindy
authors.initials: C
authors.lastname: Caldwell
authors.forename: Robert
authors.initials: R
authors.lastname: Smith
authors.forename: Theodore R
authors.initials: TR
authors.lastname: Levin
mesh_terms: D000368:Aged; D002140:California; D003113:Colonoscopy / Q000191:economics; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D003362:Cost-Benefit Analysis; D003955:Diagnostic Tests, Routine / Q000191:economics / Q000379:methods*; D055088:Early Detection of Cancer / Q000191:economics / Q000379:methods*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000191:economics; D007342:Insurance Benefits; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical
keywords: COLO; CORI; CRC; Cancer Screening; Clinical Outcomes Research Initiative; Comparative; Cost-utility Analysis; Effectiveness; FIT; FIT/COLOx1; FOBT; FS; ICER; KPNC; Kaiser Permanente Northern California; Mixed Screening Strategy; QALY; SEER; SIG; Surveillance Epidemiology and End Results; TPMG; The Permanente Medical Group; annual fecal immunological test and colonoscopy at age 66; colonoscopy alone; colorectal cancer; fecal immunological test; fecal occult blood test; flexible sigmoidoscopy; gFOBT; guaiac-based fecal occult blood test; incremental cost-effectiveness ratio; quality-adjusted life year; sigmoidoscopy