Table 5.
Prediction equations to estimate 24 h Na using correction applied for both spot Na and spot Cr using the Tanaka equation (mmoL/day).
| Statistics | Measured 24 h Urinary Sodium Excretion | Tanaka Spot 1 | Tanaka Mean Day 1 and 2 | Tanaka Adjusted Day 1 and 2 | Tanaka Mean Day 1, 2, and 3 | Tanaka Adjusted Day 1, 2, and 3 |
|---|---|---|---|---|---|---|
| Minimum | 32.00 | 124.32 | 176.45 | 182.74 | 227.93 | 204.29 |
| p5 | 49.00 | 207.34 | 225.89 | 231.07 | 244.95 | 236.30 |
| p10 | 56.00 | 238.77 | 236.59 | 287.05 | 245.80 | 293.09 |
| p25 | 66.00 | 285.11 | 283.61 | 325.21 | 276.53 | 332.74 |
| p50 | 107.00 | 396.58 | 370.48 | 374.39 | 370.83 | 377.85 |
| p75 | 154.00 | 482.93 | 415.18 | 438.87 | 431.25 | 419.99 |
| p90 | 201.00 | 559.35 | 485.55 | 478.08 | 461.72 | 458.77 |
| p95 | 220.00 | 572.75 | 500.06 | 498.03 | 477.71 | 478.86 |
| IQR | 88.00 | 197.82 | 131.56 | 113.66 | 154.72 | 87.25 |
| Maximum | 232.00 | 738.90 | 597.13 | 541.18 | 498.26 | 522.32 |
| Mean | 115.00 | 392.03 | 364.27 | 376.83 | 364.58 | 374.55 |
| SD | 56.33 | 138.88 | 97.35 | 84.72 | 83.76 | 74.80 |
| p-value * | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | |
| Spearman correlation coefficient | 0.1047 | 0.3192 | 0.1808 | 0.2372 | 0.1927 | |
| p-value correlation | 0.6343 | 0.1377 | 0.4090 | 0.2759 | 0.3784 |
* p-value of difference between measured 24 h urinary sodium excretion and each prediction equation using Tanaka was assessed by Wilcoxon’s signed rank test. Na: sodium, Cr: creatinine.