lambda_z estimation [🇷 for BE/BA]

posted by yjlee168 Homepage – Kaohsiung, Taiwan, 2008-09-25 00:41 (6060 d 17:15 ago) – Posting: # 2397
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Dear d_labes,

Yes, Helmut also comments about this. He even said it should not include Tmax and Cmax even for 1-compartment model. I read previous threads as you and Helmut pointed. I think that it is not appropriate to include Tmax and Cmax to calculate lambdaz for a drug with a 2-compartment model. However, for a drug with 1-compartment model, theoretically, it should be o.k.. :ponder: But I will think about that later.
Currently, we do not plan to include Tmax and Cmax to estimate lambdaz.
Some automatic algorithms (such as that suggested by Ace or WinNonlin) may pick Cmax to estimate lambdaz. We now allow users to pick these data points visually and manually in bear.

We will try to implement the TTT rule in bear.

About using AICs to choose appropriate data points to estimate lambdaz is very interesting. As far as I know, AIC is used to do model selection or model discrimination. Basically, we will fit different models with the same observed data (points). I really don't know if we can use AICs to vary data points to the same model (linear regression). That's why we will not try to abandon or pick some data points from the observed dataset, when doing pk/pd modeling, to a model. But it is a very interesting and innovative approach.
—
All the best,
-- Yung-jin Lee
bear v2.9.2:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan https://www.pkpd168.com/bear
Download link (updated) -> here
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