Disagreement between direct and indirect potentiometric Na+ determination in infancy and childhood.

We also found an association with the following pairwise interaction terms: age and creatinine, age and albumin, and finally hemoglobin and albumin. However, as albumin and creatinine vary with age [10], this analysis is not able to verify if albumin and creatinine play a direct or an indirect role in the mentioned associations. Age, albumin, hemoglobin, potentiometry, sodium. [Extracted from the article]