BLLOQ (or NQ-Non Quantifiable Concentrations) in PK Concentration data [NCA / SHAM]

posted by Ashwitha – India, 2017-07-09 15:02 (1132 d 09:51 ago) – Posting: # 17529
Views: 1,725


I am new to the group. But I have read couple of discussions recently and found very informative, thanks for sharing the knowledge.

I am a Programmer in Clinical domain, I develop data sets and reports on various domains.

I have a query regarding BLLOQ or NQ values in PK concentration data.
We follow certain rules to impute the NQ's in the data,
1. if there is single NQ between measurable concentrations we impute it to Null,
2. if it is leading NQ's we impute it to Zero and
3. if it is More than one consecutive NQ between measurable concentrations we impute the NQ value to Null.

So, I have done some research, not thorough, on understanding this and I found that these imputations are carefully done for input data needs for WinNonlin software and also to neither overestimate or underestimate AUC.

Could anyone please help me understand why these imputations are done, as i am confused.

Please also suggest Literature to understand the topics.

Thank you,

Edit: Category changed; see also this post #1. [Helmut]

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