auc.batch {PK}R Documentation

Estimation of the Area Under the Concentration Time Curve in Batch Designs

Description

Non-compartmental estimation of area under the concentration time curve (AUC) and area under the first moment curve (AUMC) in batch designs.

Usage

auc.batch(conc, time, exact=NA, n.interpolate=2, n.tail=3)

Arguments

conc A list of concentration levels. One element in the list should correspond to one batch. Multiple measurements per time point are expected to be adjacent to each other.
time A list of time points of concentration assessment. One element in the list should correspond to one batch. One time point for each concentration measured needs to be specified.
exact Time point for linear interpolation/extrapolation (default=NA). Currently not implemented.
n.interpolate Number of last data points used for linear interpolation/extrapolation (default=2). Currently not implemented.
n.tail Number of last data points used for tail area estimation (default=3).

Details

Estimation of the area under the concentration time curve (AUC 0-tlast) and area under the first moment curve (AUMC 0-tlast) for batch designs. In a serial sampling design only one measurement is available per subject at a specific time point, while in a batch design multiple time points are measured for each subject. AUC and AUMC (from 0 to the last time point) are calculated using the linear trapezoidal rule at the different time points.

Estimation of the linearly interpolated area under the concentration time curve (AUC 0-exact) and linearly interpolated area under the moment curve (AUMC 0-exact). The time point for linear interpolation/extrapolation must be after the last but one time point of concentration assessments.

Estimation of the total area under the concentration curve (AUC 0-infinity) and total area under the first moment curve (AUMC 0-infinity) by using a tail area correction similar as suggested by Perrier and Gibaldi (Appendix D, 1982).

Equal sample size per time point is required.

Value

An object of the class PK including AUC and AUMC estimates.

Author(s)

Thomas Jaki

References

Gibaldi M. and Perrier D. (1982). Pharmacokinetics. 2nd Edition. Marcel Dekker, New York and Basel.

Holder D. J., Hsuan F., Dixit R. and Soper K. (1999). A method for estimating and testing area under the curve in serial sacrifice, batch, and complete data designs. Journal of Biopharmaceutical Statistics, 9(3):451-464.

Jaki T. and Wolfsegger M. J. (In press). A theoretical framework for estimation of AUCs in complete and incomplete sampling designs. Statistics in Biopharmaceutical Research.

See Also

auc, auc.ci, auc.test.

Examples

## a batch design from Jaki and Wolfsegger (in press), originally in Holder et al. (1999).
conc <- list(batch1=c(0,0,0,1.75,2.2,1.58,4.63,2.99,1.52), 
             batch2=c(3.03,1.98,2.22,3.34,1.3,1.22),
             batch3=c(3.54,2.84,2.55,0.3,0.0421,0.231))
time <- list(batch1=c(0,0,0,1,1,1,6,6,6), batch2=c(2,2,2,10,10,10), batch3=c(4,4,4,24,24,24))
auc.batch(conc, time, n.tail=3)


[Package PK version 1.00 Index]