Provides methods for estimating the area under the concentration
versus time curve (AUC) and its standard error in the presence of Below the
Limit of Quantification (BLOQ) observations. Two approaches are implemented:
direct estimation using censored maximum likelihood, and a two-step approach
that first imputes BLOQ values using various methods and then computes the
AUC using the imputed data. Technical details are described in Barnett et al.
(2020), "Methods for Non-Compartmental Pharmacokinetic Analysis With
Observations Below the Limit of Quantification," Statistics in
Biopharmaceutical Research.