title: Geographic variation of racial/ethnic disparities in colorectal cancer testing among medicare enrollees.
abstract: BACKGROUND
  The Medicare population has documented racial/ethnic disparities in colorectal cancer (CRC) screening, but it is unknown whether these disparities differ across geographic regions.
  
  
  METHODS
  Among Medicare enrollees within 8 US states, we ascertained up-to-date CRC screening on December 31, 2003 (fecal occult blood testing in the prior year or sigmoidoscopy or colonoscopy in the prior 5 years). Logistic regression models tested for regional variation in up-to-date status among white versus different nonwhite populations (blacks, Asian/Pacific Islanders [APIs], Hispanics). We estimated regression-adjusted region-specific prevalence of up-to-date status by race/ethnicity and compared adjusted white versus nonwhite up-to-date prevalence across regions by using generalized least squares regression.
  
  
  RESULTS
  White versus nonwhite up-to-date status varied significantly across regions for blacks (P = .01) and APIs (P < .001) but not Hispanics (P = .62). Whereas the white versus black differences in proportion up-to-date were greatest in Atlanta (Georgia), rural Georgia, and the San Francisco Bay Area of California (range, 10%-16% differences, blacks<whites); there were no significant white versus black differences in Connecticut, Seattle (Washington) or Iowa. Whereas APIs had significantly lower up-to-date prevalence than whites in Michigan and the California regions of San Francisco, Los Angeles, and San Jose (range, 4%-15% differences, APIs<whites), APIs in Hawaii had higher up-to-date status than whites (52% vs 38% P < .001). White versus Hispanic differences were substantial but homogeneous across regions (range, 8%-16% differences, Hispanics<whites). In contrast to nonwhites, there was little geographic variation in up-to-date status among whites.
  
  
  CONCLUSIONS
  Significant geographic variation in up-to-date status among black and API Medicare enrollees is associated with heterogeneous racial/ethnic disparities for these groups across US regions.
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis Sacramento, California 95817, USA. thomas.semrad@ucdmc.ucdavis.edu
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Semrad
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Tancredi
authors.forename: Laura-Mae
authors.initials: LM
authors.lastname: Baldwin
authors.forename: Pamela
authors.initials: P
authors.lastname: Green
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Fenton
mesh_terms: D000368:Aged; D044383:Black People; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D055088:Early Detection of Cancer / Q000706:statistics & numerical data*; D005006:Ethnicity; D005260:Female; D054625:Healthcare Disparities / Q000208:ethnology*; D006630:Hispanic or Latino; D006801:Humans; D008297:Male; D006278:Medicare; D009780:Occult Blood; D012424:Rural Population; D014481:United States; D044465:White People; D001741:Black or African American