Re: Concentration values below assay limits

From n.holford@auckland.ac.nz Wed May 21 12:36:19 1997 Subject: Re: Concentration values below assay limits Eliane, Yes. But I have little experience. The real issue is why is there a BQL value at all? If you have a suitable error model you can take any "measured" value at low concs and use it in your PK analyses without having to define a BQL. But if the conc analyst will not tell you the conc but will only tell you BQL then you must resort to 'imputation' (ie. faking the data). Try telling your conc analyst that is what you are going to do :-) -- Nick Holford, Dept Pharmacology & Clinical Pharmacology University of Auckland, Private Bag 92019, Auckland, New Zealand email:n.holford@auckland.ac.nz tel:+64(9)373-7599x6730 fax:373-7556 http://www.phm.auckland.ac.nz/Staff/NHolford/nholford.html