Table 2.

Patient and geographic characteristics stratified by dialysis facility choices and Herfindahl–Hirschman Index in 2011

Patient and Geographic CharacteristicsQuartile of Facility ChoicesQuartile of Concentration Index
More CompetitiveLess CompetitiveMore CompetitiveLess Competitive
FirstSecondThirdFourthFirstSecondThirdFourth
Mean no. of facility choices or HHI19.27.23.91.50.240.360.500.75
Patient demographic and health characteristics
Age, mean60.861.462.162.161.161.162.162.1
Women, %44.644.544.945.644.544.745.345.2
White, %a,b47.450.059.859.445.751.261.361.1
Black, %a,b44.843.733.933.246.243.230.732.7
Native American, %a,b0.40.81.33.20.41.21.43.0
Asian, %a,b6.55.04.74.06.94.06.22.9
Reported Hispanic, %6.76.36.56.27.06.26.65.9
Comorbidity score, mean3.23.13.13.03.23.13.13.0
Health insurance types, %
Medicaid eligible37.636.636.538.737.636.536.838.3
Medicare as primary insurera,b62.769.571.977.664.168.172.578.0
Private group insurance4.55.15.15.04.65.25.24.8
Geographic characteristics
Rural/small town, %a,b2.53.88.420.71.12.59.923.2
Metropolitan, %a,b95.392.182.056.298.394.979.650.5
No high school education, % of HSAa22.718.017.417.821.119.017.817.5
Poverty, % of HSA19.418.817.218.019.618.516.917.8
  • Note that standardized difference quantifies the difference in means between comparison groups as a share of the pooled SD for the two groups. HHI, Herfindahl–Hirschman Index; HSA, hospital service area.

  • a Signifies >10% standardized difference in a comparison of the 1st and 4th quartiles of facility choices.

  • b Signifies >10% standardized difference in a comparison of the 1st and 4th quartiles of HHI.