Please never mind. Someone suggested tose tlag, which is a simple
and efficient enough way to do it.
Regards,
Pavel
Dear Robert,
Efficacy is frequently considered a function of AUC. (AUC is just an
integral. It is obvious how to calculate AUC any software which can
solve ODE.) A disadvantage of this model of efficacy is that the effect
is irreversable because AUC of concentration can only increase; it
cannot decrease. In many cases, a more meaningful model is a model
where AUC is calculated form time t -a to t (kind of "moving average"),
where t is time in the system of differential equations (variable T in
NONMEM). There are 2 obvious ways to calculate AUC(t-a, t). The first
is to do backward integration, which looks like a hard and resource
consuming way for NONMEM. The second one is to keep in memory AUC for
all time points used during the integration and calculate AUC(t-a,t) as
AUC(t) - AUC(t-a), there AUC(t-a) can be interpolated using two closest
time points below and above t-a.
Is there a way to access AUC for the past time points (<t) from the
integration routine? It seems like an easy thing to do.
Kind regards,
Pavel
