Table 3.

Cox models to determine association between SK (at baseline and as time dependent covariate) as continuous and categorical covariate with mortality, ESRD, and cardiovascular events

ParameterModel 1 (without Serum Albumin)Model 2 (with Serum Albumin)
HR95% CIPHR95% CIP
Mortality
    time-dependent continuous SKa
        SK = 3.4 versus 5.0 mmol/L2.401.13 to 5.092.330.95 to 5.71
        SK = 3.8 versus 5.0 mmol/L1.651.04 to 2.611.570.90 to 2.73
        SK = 6.0 versus 5.0 mmol/L1.340.59 to 3.031.590.62 to 4.04
    time-dependent categorical SK (eukalemia as reference)
        hypokalemia (≤4.0 mmol/L)1.731.02 to 2.950.041.901.00 to 3.610.05
        hyperkalemia (≥5.5 mmol/L)1.570.78 to 3.200.201.820.80 to 4.160.15
ESRD
    time-dependent continuous SKb
        SK = 3.4 versus 5.0 mmol/L1.871.25 to 2.791.560.97 to 2.52
        SK = 3.8 versus 5.0 mmol/L1.421.11 to 1.821.280.95 to 1.72
        SK = 6.0 versus 5.0 mmol/L1.260.91 to 2.141.210.83 to 1.76
    time-dependent categorical SK (eukalemia as reference)
        hypokalemia (≤4.0 mmol/L)1.691.25 to 2.290.00061.390.97 to 1.990.07
        hyperkalemia (≥5.5 mmol/L)1.020.70 to 1.480.911.090.71 to 1.680.68
ESRD or death
    time-dependent continuous SKc
        SK = 3.4 versus 5.0 mmol/L2.171.50 to 3.151.420.88 to 2.28
        SK = 3.8 versus 5.0 mmol/L1.571.25 to 1.971.240.92 to 1.66
        SK = 6.0 versus 5.0 mmol/L1.250.90 to 1.731.040.73 to 1.48
    time-dependent categorical SK (eukalemia as reference)
        hypokalemia (≤4.0 mmol/L)1.711.31 to 2.22<0.00011.071.99 to 0.021.07
        hyperkalemia (≥5.5 mmol/L)1.120.81 to 1.570.460.811.74 to 0.360.81
Cardiovascular event or death
    time-dependent continuous SKd
        SK = 3.4 versus 5.0 mmol/L1.340.86 to 2.091.040.62 to 1.74
        SK = 3.8 versus 5.0 mmol/L1.070.81 to 1.410.920.67 to 1.26
        SK = 6.0 versus 5.0 mmol/L1.841.24 to 2.741.781.17 to 2.70
    time-dependent categorical SK (eukalemia as reference)
        hypokalemia (≤4.0 mmol/L)1.330.95 to 1.860.091.130.76 to 1.670.54
        hyperkalemia (≥5.5 mmol/L)1.751.18 to 2.620.0051.691.09 to 2.600.02
  • a Model 1: β(SK2) = 0.32, P = 0.11; model 2: β(SK2) = 0.38, P = 0.10.

  • b Model 1: β(SK2) = 0.24, P = 0.007; model 2: β(SK2) = 0.18, P = 0.09.

  • c Model 1: β(SK2) = 0.72, P = 0.002; model 2: β(SK2) = 0.10, P = 0.32.

  • d Model 1: β(SK2) = 0.31, P = 0.003; model 2: β(SK2) = 0.23, P = 0.04.