title: Racial and regional differences in venous thromboembolism in the United States in 3 cohorts.
abstract: BACKGROUND
  Blacks are thought to have a higher risk of venous thromboembolism (VTE) than whites. However, prior studies are limited to administrative databases that lack specific information on VTE risk factors or have limited geographic scope.
  
  
  RESULTS
  We ascertained VTE from 3 prospective studies: the Atherosclerosis Risk in Communities Study (ARIC), the Cardiovascular Health Study (CHS), and the Reasons for Geographic and Racial Differences in Stroke study (REGARDS). We tested the association of race with VTE using Cox proportional hazard models adjusted for VTE risk factors. Over 438 090 person-years, 916 incident VTE events (302 in blacks) occurred in 51 149 individuals (17 318 blacks) who were followed up. In risk factor-adjusted models, blacks had a higher rate of VTE than whites in the CHS (hazard ratio, 1.81; 95% confidence interval, 1.20-2.73) but not ARIC (hazard ratio, 1.21; 95% confidence interval, 0.96-1.54). In REGARDS, there was a significant region-by-race interaction (P=0.01): Blacks in the Southeast had a significantly higher rate of VTE than blacks in the rest of the United States (hazard ratio, 1.63; 95% confidence interval, 1.08-2.48) that was not seen in whites (hazard ratio, 0.83; 95% confidence interval, 0.61-1.14).
  
  
  CONCLUSIONS
  The association of race with VTE differed in each cohort, which may reflect the different time periods of the studies or different regional rates of VTE. Further studies of environmental and genetic risk factors for VTE are needed to determine which underlie racial and perhaps regional differences in VTE.
authors: University of Vermont, Burlington (N.A.Z., M.C.); University of Alabama at Birmingham, Birmingham (L.A.M., S.E.J.., M.M.S.); and University of Minnesota, Minneapolis (A.R.F.., P.L.L.).
authors: Neil A
authors: NA
authors: Zakai
authors: Leslie A
authors: LA
authors: McClure
authors: Suzanne E
authors: SE
authors: Judd
authors: Monika M
authors: MM
authors: Safford
authors: Aaron R
authors: AR
authors: Folsom
authors: Pamela L
authors: PL
authors: Lutsey
authors: Mary
authors: M
authors: Cushman
mesh_terms: D000368:Aged; D044383:Black People / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D054556:Venous Thromboembolism / Q000175:diagnosis / Q000453:epidemiology* / Q000208:ethnology*; D044465:White People / Q000706:statistics & numerical data*; D001741:Black or African American
keywords: continental population groups; epidemiology; venous thrombosis