Table 2.

Patient characteristics by Gini Index quartile

CharacteristicsGini Index QuartileP Valuea
First (n=89,042)Second (n=113,865)Third (n=185,453)Fourth (n=200,676)
Black race (%)20.222.432.654.5<0.001
Male sex (%)56.255.855.453.4<0.001
Mean age ± SD (yr)64.8±14.665.0±14.664.4±14.862.8±15.2<0.001
Mean BMI ± SD (kg/m2)28.7±7.828.6±7.628.3±7.628.2±7.7<0.001
Median income (interquartile range) ($)46,054 (38,750–56,337)38,788 (32,478–48,494)37,640 (29,530–48,835)31,544 (22,791–41,658)<0.001
 Among non-Hispanic whites<0.001
  Patients (n)71,03988,343124,98291,345
  Income ($)46,889 (39,994–56,880)40,593 (35,017–50,543)41,573 (34,558–52,905)39,991 (32,115–51,428)
 Among non-Hispanic blacks<0.001
  Patients (n)18,00325,52260,471109,331
  Income ($)41,094 (30,070–53,326)29,539 (23,768–38,330)27,368 (21,568–36,205)24,682 (19,228–32,463)
Current smoker (%)6.06.66.66.0<0.001
Diabetes (%)55.955.855.154.6<0.001
Polycystic kidney disease (%)2.32.22.01.6<0.001
AIDS nephropathy (%)0.40.50.61.6<0.001
Comorbid condition (%)
 Chronic obstructive pulmonary disease10.811.310.17.7<0.001
 Congestive heart failure35.535.535.732.6<0.001
 Peripheral vascular disease16.417.015.813.0<0.001
 Cerebrovascular disease10.410.310.79.8<0.001
 Atherosclerotic heart disease29.829.928.322.8<0.001
 Cancer8.28.07.66.3<0.001
Insurance status (%)<0.001
 Employer group health insurance29.624.824.320.9
 Medicaid15.318.421.826.7
 Medicare42.943.339.635.3
 No insurance4.95.36.09.3
 Others7.48.28.47.8
Prior employment status (%)<0.001
 Employed16.715.115.516.0
 Homemaker/student/other12.310.99.910.5
 Retire: age/preference44.644.842.435.7
 Retire: disability15.817.417.718.9
 Unemployed10.711.814.518.9
  • Quartile definition for Gini Index was as follows: 0.33–0.41, 0.41–0.43, 0.43–0.46, and 0.46–0.60.

  • a Calculated per the following: ANOVA for continuous variables, chi-square test for categorical variables, and Kruskal-Wallis test for median comparison.