title: Advancing the hypothesis that geographic variations in risk factors contribute relatively little to observed geographic variations in heart disease and stroke mortality.
abstract: OBJECTIVE
  Geographic variation in risk factors may underlie geographic disparities in coronary heart disease (CHD) and stroke mortality.
  
  
  METHODS
  Framingham CHD Risk Score (FCRS) and Stroke Risk Score (FSRS) were calculated for 25,770 stroke-free and 22,247 CHD-free participants from the REasons for Geographic And Racial Differences in Stroke cohort. Vital statistics provided age-adjusted CHD and stroke mortality rates. In an ecologic analysis, the age-adjusted, race-sex weighted, average state-level risk factor levels were compared to state-level mortality rates.
  
  
  RESULTS
  There was no relationship between CHD and stroke mortality rates (r=0.04; p=0.78), but there was between CHD and stroke risk scores at the individual (r=0.68; p<0.0001) and state (r=0.64, p<0.0001) level. There was a stronger (p<0.0001) association between state-level FCRS and state-level CHD mortality (r=0.28, p=0.18), than between FSRS and stroke mortality (r=0.12, p=0.56).
  
  
  CONCLUSIONS
  Weak associations between CHD and stroke mortality and strong associations between CHD and stroke risk scores suggest that geographic variation in risk factors may not underlie geographic variations in stroke and CHD mortality. The relationship between risk factor scores and mortality was stronger for CHD than stroke.
authors.affiliation: Department of Biostatistics, School of Public Health, University of Alabama at Birmingham, Birmingham, AL, USA. ghoward@uab.edu
authors.forename: George
authors.initials: G
authors.lastname: Howard
authors.forename: Mary
authors.initials: M
authors.lastname: Cushman
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Prineas
authors.forename: Virginia J
authors.initials: VJ
authors.lastname: Howard
authors.forename: Claudia S
authors.initials: CS
authors.lastname: Moy
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Sullivan
authors.forename: Ralph B
authors.initials: RB
authors.lastname: D'Agostino
authors.forename: Leslie A
authors.initials: LA
authors.lastname: McClure
authors.forename: Leavonne
authors.initials: L
authors.lastname: Pulley
authors.forename: Monika M
authors.initials: MM
authors.lastname: Safford
mesh_terms: D000367:Age Factors; D000368:Aged; D044383:Black People / Q000706:statistics & numerical data; D016000:Cluster Analysis; D015331:Cohort Studies; D003327:Coronary Disease / Q000208:ethnology / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012111:Residence Characteristics / Q000706:statistics & numerical data; D012307:Risk Factors; D012737:Sex Factors; D020521:Stroke / Q000208:ethnology / Q000401:mortality*; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American