Helmut ★★★ ![]() ![]() Vienna, Austria, 2014-05-26 19:50 (3915 d 16:50 ago) Posting: # 13007 Views: 5,158 |
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Dear all, at the last two conferences in Budapest I discussed the issue of retesting subjects with (former) employees of the FDA.
— 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, 2014-05-27 23:52 (3914 d 12:48 ago) @ Helmut Posting: # 13009 Views: 3,979 |
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Hi Helmut! Was there a meeting in Budapest recently? Did you see Laszlo E? I had dinner with him around early May and he said he will be in Budapest... ❝ ● Performing “mini-studies” (aka retesting) was never an official recommendation. The commonly quoted sizes (at least six subjects or 20% of the main study – which ever is larger) are also an urban myth. Nope, but you can propose. ❝ ● Some studies were quite large (60–80 subjects). When asked why they didn’t opt for reference-scaling the answer was “FDA’s guidance requires a two-way crossover!” It turned out that high variability is well documented in the literature (well, that’s why the sample size was large). You will be surprised! ❝ ● Given the advanced technology in bioanalytics accessible today – requiring much smaller sampling volumes than a decade ago... I've talked to some labs who still insisted "We need no less than 4 mL sample, otherwise we can't guarantee that we can do repeats" John |