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RegisterSerum cortisol AUC [General Statistics]
Dear JPL and Yayati!
Yes, you are right. But Yayati in his original post stated only two sampling points (pre- and post treatment). IMHO in such a case AUC is meaningless. I would only compare pre- and post-treatment - and not even think about calculating an 'AUC'. In the case of cortisol a baseline correction is debatable; maybe a transformation of the post-treatment data into a percentage of pre-treatment makes sense. For a discussion of baseline values see Senn (Cross-over Trials in Clinical Research, Section 3.16, Wiley, 2nd ed. 2006).
@Yayati:
It's not considered good statistical practice to gather data and seeking a method for evaluation afterwards. We should invest the better part in planning.
❝ However, take care of any kind of pre-treatment adjustment, otherwise your
❝ AUC is biased.
Yes, you are right. But Yayati in his original post stated only two sampling points (pre- and post treatment). IMHO in such a case AUC is meaningless. I would only compare pre- and post-treatment - and not even think about calculating an 'AUC'. In the case of cortisol a baseline correction is debatable; maybe a transformation of the post-treatment data into a percentage of pre-treatment makes sense. For a discussion of baseline values see Senn (Cross-over Trials in Clinical Research, Section 3.16, Wiley, 2nd ed. 2006).
@Yayati:
It's not considered good statistical practice to gather data and seeking a method for evaluation afterwards. We should invest the better part in planning.
—
Regards, Jaime
Regards, Jaime
Complete thread:
- Serum cortisol AUC Yayati 2008-07-12 07:25
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- Serum cortisol AUC JPL 2008-07-14 12:29
- Serum cortisol AUCJaime_R 2008-07-14 15:34
- distribution of Serum cortisol AUC Yayati 2008-07-16 05:36
- Serum cortisol AUC JPL 2008-07-14 12:29
Ing. Helmut Schütz