title: Association between insurance status and mortality in individuals with albuminuria: an observational cohort study.
abstract: BACKGROUND
  In the general population, the association between uninsurance and mortality is well established. We sought to evaluate the association of health insurance status with mortality among working-age participants with albuminuria in the Third National Health and Nutrition Examination Survey, 1988-1994 (NHANES III).
  
  
  METHODS
  We used data from non-elderly adult participants (18-64) of NHANES III (1988-1994), a nationally representative study of the US civilian, noninstitutionalized population, who provided information on insurance and who had albuminuria, defined as a urine albumin-to-creatinine ratio [UACR] ≥ 30 mg/g and their subsequent mortality to December 31, 2006. Cox proportional hazards models were used to determine associations between insurance status and all-cause mortality and cardiovascular mortality in patients with CKD while adjusting in a stepwise fashion for sociodemographic factors, co-morbidities, and co-morbidity severity/control covariates.
  
  
  RESULTS
  In our sample of individuals with albuminuria (n = 903), mean estimated glomerular filtration rate (eGFR) was 101.6 ml/min/1.73 m(2) with 4.7 % with an eGFR <60. Approximately 15 % of the sample was uninsured, 18 % had public insurance and 67 % had private insurance. Compared to individuals with private insurance, those with public insurance or no insurance were significantly more likely to be a racial or ethnic minority, to have income <200 % below the federal poverty level, to have less than high school education; and they were less likely to be married and to report good or excellent health, all p < 0.05. Being uninsured or having public insurance was associated with increased all-cause mortality in the fully adjusted model (HR 2.97 and 3.65, respectively, p < 0.05). There was no significant relationship between insurance status and cardiovascular mortality.
  
  
  CONCLUSIONS
  In a nationally representative sample of individuals with albuminuria, uninsurance and public insurance were associated with increased mortality compared to the private insurance even after controlling for sociodemographic, health status, and health care variables. Improving access to care and the quality of care received may potentially reduce mortality in individuals with evidence of early CKD.
authors.affiliation: University of Chicago Medicine, 5841 S. Maryland, MC 5000, Chicago, IL, 60637, USA. msaunder@medicine.bsd.uchicago.edu.
authors.forename: Milda R
authors.initials: MR
authors.lastname: Saunders
authors.affiliation: University of Illinois at Chicago, 820 Wood St, MC 793, Chicago, IL, 60612, USA. aricar2@uic.edu.
authors.forename: Ana Catherine
authors.initials: AC
authors.lastname: Ricardo
authors.affiliation: University of Illinois at Chicago, 820 Wood St, MC 793, Chicago, IL, 60612, USA. jinsongc@uic.edu.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Chen
authors.affiliation: University of Chicago Medicine, 5841 S. Maryland, MC 2007, Chicago, IL, 60637, USA. mchin@medicine.bsd.uchicago.edu.
authors.forename: Marshall H
authors.initials: MH
authors.lastname: Chin
authors.affiliation: University of Illinois at Chicago, 820 Wood St, MC 793, Chicago, IL, 60612, USA. jplash@uic.edu.
authors.forename: James P
authors.initials: JP
authors.lastname: Lash
mesh_terms: D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000453:epidemiology*; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D015331:Cohort Studies; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D006297:Health Services Accessibility; D006304:Health Status; D006801:Humans; D019458:Insurance Coverage / Q000706:statistics & numerical data*; D007348:Insurance, Health / Q000706:statistics & numerical data*; D008297:Male; D017533:Marital Status; D017057:Medically Uninsured / Q000706:statistics & numerical data*; D008875:Middle Aged; D008913:Minority Groups / Q000706:statistics & numerical data; D009026:Mortality; D009749:Nutrition Surveys; D011203:Poverty / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology* / Q000401:mortality; D014481:United States / Q000453:epidemiology; D055815:Young Adult