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Rajdeep ★ New Delhi, India, 2010-06-18 16:02 (5434 d 08:12 ago) Posting: # 5534 Views: 7,317 |
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Dear All In case of an ambulatory sample collection, our CRO tends to maintain a 10 minute window period for collection. But if the subject turns up an hour late, it is considered to be a deviation. But sample still is collected. What if the subject wants to leave early (1 hour before scheduled collection time). Can his/her ambulatory sample be collected earlier then? Please give your thoughts on the same. — Best regards Rajdeep Mukherjee Protocol Developer |
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Dr_Dan ★★ Germany, 2010-06-18 17:13 (5434 d 07:01 ago) @ Rajdeep Posting: # 5535 Views: 6,117 |
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Dear Rajdeep It is always better to have a sample, even if this sample is not collected at scheduled time. You will have a protocol deviation but this is irrelevant (as long as this deviation is not too big) since your calculation is based on real times (and not on scheduled times). I often observe time deviations at ambulatory sample collection in order to consider subject´s personal interests. I would agree to collect an ambulatory sample 1 hour earlier if not otherwise possible. Kind regards Dan — Kind regards and have a nice day Dr_Dan |
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Ohlbe ★★★ France, 2010-06-18 18:50 (5434 d 05:24 ago) @ Dr_Dan Posting: # 5536 Views: 6,834 |
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Dear Rajdeep and Dan, I agree with Dan: no consequence on the trial data / bioequivalence evaluation as you will be using real sampling times. Whether you consider it as a protocol deviation or not is another question, but as anyway you will have in your report a table listing all sampling time deviations it is not really an issue. If a subject arrives late for an ambulatory sample you can't really help it. It may result in a protocol deviation, but it's not your fault. All you can do is remind the subject to come on time for the next sample. But I'm more uncomfortable about samples taken early. The subjects have been informed about the protocol constraints and they have given their consent. If the subject arrives early and you take the sample before the scheduled time, then you deliberately and voluntarily violate the protocol... which would be a GCP violation. Of course that's better than having a subject drop out, but I think you really should avoid taking the sample too early. Regards Ohlbe — Regards Ohlbe |
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Helmut ★★★   Vienna, Austria, 2010-06-19 17:49 (5433 d 06:25 ago) @ Ohlbe Posting: # 5541 Views: 6,112 |
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Dear all! I agree – almost.  See also the EMA’s GL (4.1.5 Characteristics to be investigated, Pharmacokinetic parameters): Actual time of sampling should be used in the estimation of the pharmacokinetic parameters. At the recent EGA-symposium on BE we had a little discussion about AUC72. Imagine a situation, where in some subjects the value at 72 h is <LLOQ, and the previous sampling time point was 60 h. If the ‘true’ relative bioavailability is 100%, in balanced studies we face an equal chance for both formulations to show values at 72 h below the LLOQ. Overall we would get an unbiased estimate comparing AUC60 to AUC72. But if the ‘true’ relative bioavailability is ≠100%, the PE will be biased away from 100%.![[image]](img/uploaded/image485.png) Example: the true value is 95% – we will expect more subjects after the test to show values below the LLOQ than after reference. If we base our decision on individual AUCt-ratios, the estimate will be <95%. In other words, the patient’s risk will not be affected (that’s the reason why regulators are not worried about apples and oranges), but the producer’s risk will increase.See also these threads:Conclusion: Keep deviations as small as possible and try to set up the bioanalytical method in such a way that you are able to measure the last concentration. — Dif-tor heh smusma 🖖🏼 Довге життя Україна! ![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png) Helmut Schütz ![[image]](https://static.bebac.at/img/CC by.png) The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
Ing. Helmut Schütz