1.   This formula takes into account the majority of solutes present in normal serum.

2.   All patients had normal serum concentrations of liver enzymes and bilirubin and were included consecutively in the study.

3.   All patients had normal serum creatinine values at the time of investigation.

4.   All controls had normal serum creatinine concentrations.

5.   He had, however, at the time of investigation a normal serum creatinine value.