The estimation of moments: a technical note.

The calculation of several common pharmacokinetic parameters requires estimates of both the area under the curve of the concentration of the drug in a sampled fluid vs. time, and also the first moment about t = 0 of this area. It is proposed that the methods used to estimate these quantities should make consistent assumptions about the concentration of the drug. There appears to be an inconsistency in the standard published formulas in the case where concentration is interpolated linearly. A more consistent formula is derived.