NCIt definition : The determination of the amount of unmeasured anions (computed as the difference between
the sum of serum sodium and serum potassium, and the sum of the serum bicarbonate
and chloride) present in a sample.;
Alternative definition : CDISC: A computed estimate of the unmeasured anions (computed as the difference between
the sum of serum sodium serum potassium and the sum of the serum bicarbonate chloride)
in a biological specimen.;