Table 1.

Patient characteristics by race

CharacteristicsAll (n=589,036)Black (n=213,327)White (n=375,709)P Valuea
Male sex (%)54.950.357.5<0.001
Mean age ± SD (yr)64.0±14.958.8±15.067.0±14.0<0.001
Mean BMI ± SD (kg/m2)28.4±7.628.8±8.028.1±7.4<0.001
Median income (interquartile range) ($)37,500 (28,845–48,165)26,742 (20,765–35,964)41,922 (35,168–52,743)<0.001
Gini Index (%)<0.001
 First quartile15.18.418.9
 Second quartile19.312.023.5
 Third quartile31.528.433.3
 Fourth quartile34.151.324.3
Residential segregation (%)<0.001
 First quartile10.39.110.9
 Second quartile16.510.519.9
 Third quartile22.318.724.3
 Fourth quartile51.061.844.8
Current smoker (%)6.36.56.2<0.001
Diabetes (%)55.256.754.3<0.001
Polycystic kidney disease (%)2.01.02.5<0.001
AIDS nephropathy (%)0.92.30.1<0.001
Comorbid condition (%)
 Chronic obstructive pulmonary disease9.65.312.1<0.001
 Congestive heart failure34.629.437.5<0.001
 Peripheral vascular disease15.210.018.1<0.001
 Cerebrovascular disease10.29.810.5<0.001
 Atherosclerotic heart disease27.016.333.0<0.001
 Cancer7.34.68.9<0.001
Insurance status (%)<0.001
 Employer group health insurance24.022.524.9
 Medicaid21.833.215.4
 Medicare39.425.147.4
 No insurance6.811.54.2
 Others8.07.88.1
Prior employment status (%)<0.001
 Employed15.818.914.0
 Homemaker/student/other10.710.510.8
 Retire: age/preference40.926.948.9
 Retire: disability17.720.616.1
 Unemployed14.923.010.3
  • Quartile definitions for Gini Index, and residential segregation were as follows: Gini Index, 0.33–0.41, 0.41–0.43, 0.43–0.46, and 0.46–0.60; for residential segregation, 0–39.50, 39.50–48.95, 48.95–58.60, and 58.60–94.00.

  • a Calculated per the following: t test for continuous variables, chi-square test for categorical variables, and Wilcoxon-Mann-Whitney test for median comparison.