This function calculates the variance of the area under the first moment
curve (AUMC) for sparse PK data. It follows the same methodology as
var_sparse_auc() but applies to the moment curve (time × concentration).
Arguments
- sparse_pk
A sparse_pk object from
as_sparse_pk()
Details
Equation 7.vii in Nedelman and Jia, 1998 is adapted for AUMC:
$$var\left(\hat{AUMC}\right) = \sum\limits_{i=0}^m\left(\frac{w_i^2 s_i^2}{r_i}\right) + 2\sum\limits_{i<j}\left(\frac{w_i w_j r_{ij} s_{ij}}{r_i r_j}\right)$$
where the variance and covariance terms are calculated on the moment curve (time × concentration) rather than concentration alone.
The degrees of freedom are calculated as described in equation 6 of the same
paper, reusing the structure from var_sparse_auc().