NONMEM Users Network Archive

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Re: ETAs & SIGMA in external validation

From: Jakob Ribbing <jakob.ribbing>
Date: Fri, 13 Apr 2018 18:04:10 +0200

Hi Tingjie,

Assuming (zero and) negative parameter values are not allowed, you =
could change from e.g. a linear model to a power model, which is as =
close as possible to the linear model, in the range of covariate values =
from the original publication.

If the publication lists e.g. median, mean and 95% CI of the covariate =
values (maybe this is hoping for too much?), then you can generate e.g. =
a normal or log-normal distribution of covariate values that reflect =
these statistics as closely as possible.
Then you can optimize the power model to resemble the linear model as =
closely as possible on these covariate-parameter data.

Best wishes


Jakob Ribbing, Ph.D.

Senior Consultant, Pharmetheus AB

Cell/Mobile: +46 (0)70 514 33 77

Jakob.Ribbing <>

Phone, Office: +46 (0)18 513 328

Uppsala Science Park, Dag Hammarskjölds väg 52B

SE-752 37 Uppsala, Sweden

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Received on Fri Apr 13 2018 - 12:04:10 EDT

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