Table 3.
Cox regression analysis of hypophosphatemia versus mortality risk
| Model | Hypophosphatemia Category, HR [95% CI] | Lowest Serum Phosphate per 1 mg/dl | |||
|---|---|---|---|---|---|
| Absent | Mild | Severe | HR [95% CI] | P Value | |
| All-cause mortality (295 events) | |||||
| Crude | Reference | 1.01 [0.69 to 1.47] | 0.97 [0.67 to 1.41] | 0.93 [0.74 to 1.19] | 0.59 |
| Model 1 | Reference | 0.96 [0.65 to 1.40] | 0.89 [0.61 to 1.30] | 0.85 [0.67 to 1.09] | 0.20 |
| Model 2 | Reference | 1.01 [0.69 to 1.48] | 1.02 [0.69 to 1.50] | 0.93 [0.71 to 1.20] | 0.69 |
| Model 3 | Reference | 1.14 [0.68 to 1.90] | 1.21 [0.72 to 2.03] | 0.92 [0.73 to 1.35] | 0.96 |
| Model 4 | Reference | 0.93 [0.55 to 1.58] | 0.98 [0.58 to 1.67] | 0.90 [0.66 to 1.23] | 0.53 |
| Model 5 | Reference | 1.02 [0.59 to 1.80] | 1.19 [0.68 to 2.08] | 1.08 [0.77 to 1.52] | 0.66 |
| Model 6 | Reference | 1.02 [0.60 to 1.72] | 1.18 [0.70 to 1.99] | 1.15 [0.82 to 1.63] | 0.42 |
| Cardiovascular mortality (94 events) | |||||
| Crude | Reference | 0.73 [0.42 to 1.29] | 0.58 [0.33 to 1.02] | 0.45 [0.28 to 0.63] | <0.001 |
| Model 1 | Reference | 0.65 [0.37 to 1.16] | 0.53 [0.30 to 0.94]a | 0.40 [0.29 to 0.56] | <0.001 |
| Model 2 | Reference | 0.65 [0.37 to 1.15] | 0.53 [0.29 to 0.97]a | 0.38 [0.27 to 0.55] | <0.001 |
| Model 3 | Reference | 0.64 [0.35 to 1.18] | 0.50 [0.26 to 0.95]a | 0.39 [0.25 to 0.60] | <0.001 |
| Model 4 | Reference | 0.62 [0.32 to 1.18] | 0.44 [0.22 to 0.88]a | 0.38 [0.24 to 0.59] | <0.001 |
| Model 5 | Reference | 0.44 [0.21 to 0.91]a | 0.36 [0.17 to 0.77]b | 0.39 [0.24 to 0.64] | <0.001 |
| Model 6 | Reference | 0.45 [0.21 to 0.95]a | 0.38 [0.17 to 0.84]a | 0.36 [0.21 to 0.61] | <0.001 |
| Noncardiovascular mortality (176 events) | |||||
| Crude | Reference | 0.85 [0.57 to 1.27] | 0.83 [0.56 to 1.23] | 0.91 [0.69 to 1.19] | 0.49 |
| Model 1 | Reference | 0.84 [0.56 to 1.25] | 0.80 [0.54 to 1.19] | 0.85 [0.65 to 1.12] | 0.25 |
| Model 2 | Reference | 0.93 [0.61 to 1.40] | 1.00 [0.66 to 1.52] | 1.01 [0.74 to 1.35] | 0.99 |
| Model 3 | Reference | 1.14 [0.68 to 1.90] | 1.21 [0.72 to 2.03] | 1.16 [0.82 to 1.64] | 0.40 |
| Model 4 | Reference | 0.93 [0.55 to 1.58] | 0.98 [0.58 to 1.67] | 1.04 [0.73 to 1.52] | 0.80 |
| Model 5 | Reference | 1.03 [0.59 to 1.80] | 1.19 [0.68 to 2.08] | 1.22 [0.85 to 1.79] | 0.28 |
| Model 6 | Reference | 1.04 [0.59 to 1.83] | 1.27 [0.71 to 2.25] | 1.32 [0.89 to 1.96] | 0.15 |
Model 1: adjusted for recipient age and sex. Model 2: model 1 plus eGFR at the time of the lowest phosphate. Model 3: model 2 plus donor age and sex, donor type, cold ischemia time, delayed graft function, and proteinuria (at the time of the lowest serum phosphate). Model 4: model 3 plus total number of HLA mismatches, acute rejection, induction and maintenance immunosuppressive use, and panel of reactive antibodies. Model 5: model 4 plus cardiovascular risk factors (dialysis vintage, smoking status, pretransplant diabetes mellitus, and cardiovascular history). Model 6: model 5 plus phosphate supplementation, vitamin D supplementation, vitamin D supplementation pretransplantation, and corrected calcium concentrations (before transplantation and at the time of the lowest serum phosphate). HR, hazard ratio; 95% CI, 95% confidence interval.
P<0.05.
P<0.01.