title: Combination aspirin and/or calcium chemoprevention with colonoscopy in colorectal cancer prevention: cost-effectiveness analyses.
abstract: BACKGROUND
  Clinical and cohort studies have shown that low-dose aspirin and calcium are effective low-risk strategies for primary prevention of colorectal cancer (CRC). We compared the cost-effectiveness of aspirin and calcium chemoprevention used with colonoscopy for primary prevention of CRCs.
  
  
  METHODS
  Markov chain Monte Carlo simulations for a population of 100,000 persons, with a colonoscopy compliance rate of 50%, were used for the analysis. If adenomas were detected, colonoscopy was repeated every 4 years until no adenomas were evident. Data sources included adenoma transition rates, initial adenoma and CRC incidences, and treatment complication rates from existing literature. Age-adjusted U.S. standard population mortality rates were used and costs were from Medicare reimbursement data. The target population was U.S. adults, undergoing CRC screening from ages 50 to 75 years.
  
  
  RESULTS
  Outcomes included incremental cost-effectiveness ratios (ICER), life-years saved (LYS), and cancer-free years saved (CFYS). The ICER per LYS for colonoscopy alone dominated compared with no screening. Compared with colonoscopy alone, colonoscopies with aspirin (ICER = $12,950/LYS) or calcium (ICER = $13,041/LYS) were the next most cost-effective strategies. ICERs per CFYS were $3,061 and $2,317 for aspirin and calcium, respectively, when added to colonoscopy. Sensitivity analyses indicated that initial prevalence of adenomas was a main determinant of prevention cost-effectiveness.
  
  
  CONCLUSIONS
  Low-dose aspirin or calcium supplementation may be beneficial when added to colonoscopy, for optimum CRC prevention, at small incremental costs.
  
  
  CONCLUSIONS
  Cost-effectiveness analyses suggest that aspirin and calcium in combination with colonoscopies are cost-effective for CRC prevention in average-risk populations.
authors.affiliation: Corresponding Author: Barbara C. Pence, Department of Pathology, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, USA. Barbara.pence@ttuhsc.edu
authors.forename: Barbara C
authors.initials: BC
authors.lastname: Pence
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Belasco
authors.forename: Conrad P
authors.initials: CP
authors.lastname: Lyford
mesh_terms: D000236:Adenoma / Q000188:drug therapy / Q000191:economics* / Q000401:mortality; D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000191:economics*; D001241:Aspirin / Q000008:administration & dosage / Q000191:economics*; D002118:Calcium / Q000008:administration & dosage / Q000191:economics*; D015331:Cohort Studies; D003113:Colonoscopy / Q000191:economics*; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000191:economics* / Q000401:mortality; D003198:Computer Simulation; D003362:Cost-Benefit Analysis; D019587:Dietary Supplements; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D009010:Monte Carlo Method; D011379:Prognosis; D012372:ROC Curve; D012307:Risk Factors; D015996:Survival Rate
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin; D002118:Calcium