Correlation between sodium and potassium excretion in 24- and 12-h urine samples. J.G. Mill, A.B.T. da Silva, M.P. Baldo, M.C.B. Molina and S.L. Rodrigues. Braz J Med Biol Res 2012; 45: 799-805

Figure 2. Correlation between sodium-creatinine ratio and potassium-creatinine ratio calculated with urine collected during the night and during a 24-h period. The Figure shows the regression line and the 95% confidence interval of the regression. r = Pearson correlation coefficient.