GM ★ India, 2018-06-29 07:47 (2099 d 17:00 ago) Posting: # 18992 Views: 3,299 |
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Hello All, Hope all are doing well. As per the Bioanalytical guidance of FDA, all values <LLQ should be declared as zero. But my doubt is, is there any possibility to use the actual values measured for calculating key parameters? If yes, how this can be justify? B’coz, we are not getting best fit (Rsq<0.8) when considering zero instead of actual values. Thankyou in advance. GM. — Best Regards, GM |
Ohlbe ★★★ France, 2018-06-29 14:00 (2099 d 10:47 ago) (edited by Ohlbe on 2018-06-29 17:11) @ GM Posting: # 18995 Views: 2,731 |
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Dear GM, ❝ As per the Bioanalytical guidance of FDA, all values <LLQ should be declared as zero. ❝ ❝ But my doubt is, is there any possibility to use the actual values measured for calculating key parameters? In BE ? Not the slightest. Nada. Forget it. ❝ B’coz, we are not getting best fit (Rsq<0.8) when considering zero instead of actual values. So what ? Who says it has to be < 0.8 ? The question is rather: was your LLOQ low enough ? What you're describing sounds a bit like you're not able to follow the terminal elimination phase but are getting a mix of distribution + elimination. If you messed up, you can't make up for it by extrapolating below your LLOQ, you'll have to re-develop your method, validate, re-assay. What is your LLOQ, and what is the Cmax range in your study ? Edit, to make sure there is no misunderstanding: when you write ❝ B’coz, we are not getting best fit (Rsq<0.8) when considering zero instead of actual values. — Regards Ohlbe |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2018-06-29 14:15 (2099 d 10:31 ago) @ GM Posting: # 18997 Views: 2,738 |
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Hi GM, ❝ As per the Bioanalytical guidance of FDA, all values <LLQ should be declared as zero. No more – see this thread. For the other points I agree with Ohlbe. — Dif-tor heh smusma 🖖🏼 Довге життя Україна! ![]() Helmut Schütz ![]() The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
jag009 ★★★ NJ, 2018-06-29 22:49 (2099 d 01:57 ago) @ Helmut Posting: # 18999 Views: 2,632 |
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Hi Helmut! ❝ ❝ As per the Bioanalytical guidance of FDA, all values <LLQ should be declared as zero. ❝ No more – see this thread. For the other points I agree with Ohlbe. I have never seen values below LLQ declared as 0 in any reports. ![]() |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2018-06-29 23:00 (2099 d 01:46 ago) @ jag009 Posting: # 19001 Views: 2,669 |
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Hi John! ❝ ❝ ❝ As per the Bioanalytical guidance of FDA, all values <LLQ should be declared as zero. ❝ ❝ No more – see this thread. For the other points I agree with Ohlbe. ❝ ❝ I have never seen values below LLQ declared as 0 in any reports. Lucky you. Was indeed stated in the FDA’s 2013 draft. Bizarre. Was a big issue at the first Crystal City (aka Arlington I) conference in 1990. People were shouting at each at other. It was very strange that “zero” reached out from the grave in the draft… — Dif-tor heh smusma 🖖🏼 Довге життя Україна! ![]() Helmut Schütz ![]() The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |