Development and double cross-validation of new spot urine sodium equation to predict 24-h urine sodium in the Malaysian population

Table 5 Mean bias limit of agreement between 24-h urinary sodium and new predicting equation, TANAKA and INTERSALT equations

Equation	Mean bias (95% CI)	Upper limit	Lower limit
Predicting equation	− 0.35 (− 72.26, 71.56)	1986.89	− 1987.60
Tanaka¹	629.83 (532.19, 727.47)	3327.99	− 2068.33
INTERSALT²	360.82 (284.34, 437.29)	2473.99	− 1752.35

¹Tanaka, equation (2.54 ÷ 1000 × 23 × [spotNa (mmol/L)/(spotCr (mg/dL) × 10] × [− 2.04 × age (years) + 14.89 × weight (kg) + 16.14 × height (cm) − 224.45]}^0.392
²INTERSALT, equation (male: 2.54 ÷ 1000 × 23 {25.46 + [0.46 × spotNa (mmol/L)] − [2.75 × spotCr (mmol/L)] − [0.13 × spot K (mmol/L)] + [4.10 × BMI ] + [0.26 × age]. Female: 2.54 ÷ 1000 × 23 {5.07 + [0.34 × spotNa (mmol/L)] − [2.16 × spotCr( mmol/L)] − [0.09 × spot K (mmol/L)] + [2.39 × BMI ] + [2.35 × age − [0.03 × age² (years)]

ISSN: 2072-1315