title: Low income, community poverty and risk of end stage renal disease.
abstract: BACKGROUND
  The risk of end stage renal disease (ESRD) is increased among individuals with low income and in low income communities. However, few studies have examined the relation of both individual and community socioeconomic status (SES) with incident ESRD.
  
  
  METHODS
  Among 23,314 U.S. adults in the population-based Reasons for Geographic and Racial Differences in Stroke study, we assessed participant differences across geospatially-linked categories of county poverty [outlier poverty, extremely high poverty, very high poverty, high poverty, neither (reference), high affluence and outlier affluence]. Multivariable Cox proportional hazards models were used to examine associations of annual household income and geospatially-linked county poverty measures with incident ESRD, while accounting for death as a competing event using the Fine and Gray method.
  
  
  RESULTS
  There were 158 ESRD cases during follow-up. Incident ESRD rates were 178.8 per 100,000 person-years (105 py) in high poverty outlier counties and were 76.3 /105 py in affluent outlier counties, p trend=0.06. In unadjusted competing risk models, persons residing in high poverty outlier counties had higher incidence of ESRD (which was not statistically significant) when compared to those persons residing in counties with neither high poverty nor affluence [hazard ratio (HR) 1.54, 95% Confidence Interval (CI) 0.75-3.20]. This association was markedly attenuated following adjustment for socio-demographic factors (age, sex, race, education, and income); HR 0.96, 95% CI 0.46-2.00. However, in the same adjusted model, income was independently associated with risk of ESRD [HR 3.75, 95% CI 1.62-8.64, comparing the <$20,000 income group to the >$75,000 group]. There were no statistically significant associations of county measures of poverty with incident ESRD, and no evidence of effect modification.
  
  
  CONCLUSIONS
  In contrast to annual family income, geospatially-linked measures of county poverty have little relation with risk of ESRD. Efforts to mitigate socioeconomic disparities in kidney disease may be best appropriated at the individual level.
authors.affiliation: Division of Nephrology, Department of Medicine, Johns Hopkins Medical Institutions, 301 Mason F, Lord Drive, Suite 2500, Baltimore, MD 21224, USA. dcrews1@jhmi.edu.
authors.forename: Deidra C
authors.initials: DC
authors.lastname: Crews
authors.forename: Orlando M
authors.initials: OM
authors.lastname: Gutiérrez
authors.forename: Stacey A
authors.initials: SA
authors.lastname: Fedewa
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Luthi
authors.forename: David
authors.initials: D
authors.lastname: Shoham
authors.forename: Suzanne E
authors.initials: SE
authors.lastname: Judd
authors.forename: Neil R
authors.initials: NR
authors.lastname: Powe
authors.forename: William M
authors.initials: WM
authors.lastname: McClellan
mesh_terms: D005260:Female; D006801:Humans; D015994:Incidence; D007182:Income; D007676:Kidney Failure, Chronic / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D011203:Poverty; D016016:Proportional Hazards Models; D012111:Residence Characteristics; D012307:Risk Factors; D012923:Social Class; D014481:United States / Q000453:epidemiology