Table 1.
Study group characteristics.
Fig 1.
Correlations between spot urine and 24-hour urinary potassium measurements.
1a: Potassium level in the spot urine sample vs. potassium level in the 24-hour urine collection (r = 0.47, P<0.001). 1b: Potassium level in the spot urine sample vs. 24-hour urinary potassium excretion (r = 0.28, P<0.001). 1c: Potassium/creatinine ratio in the spot urine sample vs. 24-hour urinary potassium excretion (r = 0.38, P<0.001). 1d: Potassium/creatinine ratio in the spot urine sample vs. 24-hour urinary potassium/creatinine ratio (r = 0.69, P<0.001).
Table 2.
Correlations between spot urine and 24-hour urine collection measurements.
Fig 2.
The Bland-Altman plot showing the difference between measured and estimated (PAHO formula) 24-hour urinary potassium excretion plotted against the mean 24-hour urinary potassium excretion by the two methods (mmol/d). Dashed lines indicate 95% limits of agreement (±1.96 SD).
Fig 3.
Receiver-operating characteristic (ROC) curves for the potassium/creatinine ratio in spot urine samples.
The ROC curve for cut-off 24-hour urinary potassium excretion of 60 mmol/24 h was omitted for clarity. AUC, area under the curve.
Fig 4.
Receiver-operating characteristic (ROC) curves for the estimated 24-hour urinary potassium excretion.
The ROC curve for cut-off 24-hour urinary potassium excretion of 60 mmol/24 h was omitted for clarity. AUC, area under the curve.