CrcL or Cr in pediatric model
I have an interesting question I'd like to get the group's collective opinion
on. I am fitting a pediatric and adult pk dataset. I have fixed weight a
priori to its allometric exponents in the model. When I test serum creatinine
and estimated creatinine clearance equation as covariates in the model (power
function), both are statistically significant. CrCL appears to be a better
predictor than serum Cr (LRT = 22.7 vs 16.7). I have an issue with using CrCL
as a predictor in the model since it's estimate is based on weight and weight
is already in the model. Also, there might be collinearity issues with CrCL
and weight in the same model, even though they are both significant. Does
anyone have a good argument for using CrCL in the model instead of serum Cr?
Thanks
Pete bonate
Peter L. Bonate, PhD, FCP
Genzyme Corporation
Senior Director
Clinical Pharmacology and Pharmacokinetics
4545 Horizon Hill Blvd
San Antonio, TX 78229 USA
[email protected]
phone: 210-949-8662
fax: 210-949-8219
crackberry: 210-315-2713
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