title: Geographic variation in cancer-related imaging: Veterans Affairs health care system versus Medicare.
abstract: BACKGROUND
  Geographic variations in use of medical services have been interpreted as indirect evidence of wasteful care. Less overuse of services, however, may not be reliably associated with less geographic variation.
  
  
  OBJECTIVE
  To compare average use and geographic variation in use of cancer-related imaging between fee-for-service Medicare and the Department of Veterans Affairs (VA) health care system.
  
  
  METHODS
  Observational analysis of cancer-related imaging from 2003 to 2005 using Medicare and VA utilization data linked to cancer registry data. Multilevel models, adjusted for sociodemographic and tumor characteristics, were used to estimate mean differences in annual imaging use between cohorts of Medicare and VA patients within geographic areas and variation in use across areas for each cohort.
  
  
  METHODS
  40 hospital referral regions.
  
  
  METHODS
  Older men with lung, colorectal, or prostate cancer, including 34,475 traditional Medicare beneficiaries (Medicare cohort) and 6835 VA patients (VA cohort).
  
  
  METHODS
  Per-patient count of imaging studies for which lung, colorectal, or prostate cancer was the primary diagnosis (each study weighted by a standardized price), and a direct measure of overuse-advanced imaging for prostate cancer at low risk for metastasis.
  
  
  RESULTS
  Adjusted annual use of cancer-related imaging was lower in the VA cohort than in the Medicare cohort (price-weighted count, $197 vs. $379 per patient; P < 0.001), as was annual use of advanced imaging for prostate cancer at low risk for metastasis ($41 vs. $117 per patient; P < 0.001). Geographic variation in cancer-related imaging use was similar in magnitude in the VA and Medicare cohorts.
  
  
  CONCLUSIONS
  Observational study design.
  
  
  CONCLUSIONS
  Use of cancer-related imaging was lower in the VA health care system than in fee-for-service Medicare, but lower use was not associated with less geographic variation. Geographic variation in service use may not be a reliable indicator of the extent of overuse.
  
  
  BACKGROUND
  Doris Duke Charitable Foundation and Department of Veterans Affairs Office of Policy and Planning.
authors.forename: J Michael
authors.initials: JM
authors.lastname: McWilliams
authors.forename: Jesse B
authors.initials: JB
authors.lastname: Dalton
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Landrum
authors.forename: Austin B
authors.initials: AB
authors.lastname: Frakt
authors.forename: Steven D
authors.initials: SD
authors.lastname: Pizer
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Keating
mesh_terms: D015179:Colorectal Neoplasms / Q000175:diagnosis; D003952:Diagnostic Imaging / Q000706:statistics & numerical data*; D018588:Fee-for-Service Plans; D006300:Health Services Misuse; D006787:Hospitals, Veterans / Q000191:economics*; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis; D008297:Male; D006278:Medicare / Q000191:economics*; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000175:diagnosis*; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000473:pathology; D012307:Risk Factors; D014481:United States; D014493:United States Department of Veterans Affairs / Q000191:economics