Multivariate Cox proportional hazard model of first heart failure event during follow-up in patients on hemodialysis (indoxyl sulfate entered as a continuous or dichotomous variable)
| Model | Hazard Ratio | 95% Confidence Interval | P value |
|---|---|---|---|
| Indoxyl sulfate (continuous variable) | |||
| Unadjusted | 1.02 | 1.01 to 1.03 | 0.001 |
| Model 1 | 1.02 | 1.01 to 1.03 | 0.001 |
| Model 2 | 1.02 | 1.01 to 1.04 | <0.001 |
| Model 3 | 1.02 | 1.01 to 1.03 | 0.003 |
| Model 4 | 1.03 | 1.01 to 1.04 | 0.002 |
| Model 5 | 1.03 | 1.01 to 1.04 | 0.001 |
| Model 6 | 1.02 | 1.01 to 1.03 | 0.001 |
| Model 7 | 1.02 | 1.01 to 1.04 | 0.001 |
| Model 8 | 1.02 | 1.01 to 1.03 | <0.01 |
| Model 9 | 1.02 | 1.01 to 1.03 | <0.001 |
| Model 10 | 1.04 | 1.02 to 1.06 | <0.001 |
| Indoxyl sulfate (dichotomous variable) | |||
| Unadjusted | 3.49 | 1.97 to 6.20 | <0.001 |
| Model 1 | 3.66 | 2.05 to 6.56 | <0.001 |
| Model 2 | 3.38 | 1.90 to 6.02 | <0.001 |
| Model 3 | 4.14 | 2.07 to 8.26 | <0.001 |
| Model 4 | 4.36 | 2.13 to 8.90 | 0.001 |
| Model 5 | 3.95 | 2.09 to 7.47 | <0.001 |
| Model 6 | 2.49 | 1.30 to 4.76 | <0.01 |
| Model 7 | 3.42 | 1.82 to 6.42 | <0.001 |
| Model 8 | 3.78 | 2.00 to 7.15 | <0.001 |
| Model 9 | 3.79 | 2.13 to 6.74 | <0.001 |
| Model 10 | 5.31 | 2.43 to 11.58 | <0.001 |
Model 1: adjusted for age, sex, and body mass index. Model 2: adjusted for history of primary hypertension, coronary heart disease, and diabetes. Model 3: adjusted for urinary volume, ultrafiltration volume, average interdialytic weight gain, residual renal function, and single-pool Kt/V. Model 4: adjusted for albumin, prealbumin, BUN, serum creatinine, uric acid, and normalized protein nitrogen appearance rate. Model 5: adjusted for LDL-cholesterol, HDL-cholesterol, apoprotein-A, apoprotein-B, and homocysteine. Model 6: adjusted for P, Ca×P, intact parathyroid hormone, and 25-hydroxy vitamin D. Model 7: adjusted for high-sensitivity C-reactive protein and β2-microglobulin. Model 8: adjusted for left ventricular mass index and left ventricular ejection fraction. Model 9: adjusted for history of taking calcium channel blocker, angiotensin conversion enzyme inhibitor, angiotensin receptor blocker, β-blocker, α-blocker, aspirin, and statin. Model 10: adjusted for hierarchically selected covariates of age, systolic BP, history of primary hypertension, history of coronary heart disease, history of diabetes, prealbumin, 25-hydroxy vitamin D, LDL-cholesterol, apoprotein-B, left ventricular mass index, and left ventricular ejection fraction. In Model 10, the backward conditional method was used.