...and a bonus question [General Sta­tis­tics]

posted by Helmut Homepage – Vienna, Austria, 2018-02-09 20:43 (2315 d 11:19 ago) – Posting: # 18390
Views: 16,008

Hi ElMaestro,

updated version:


Runtime 0.92 seconds. 7470 subjects in 142 data sets of 114 2×2×2 studies (86 analytes).
Evaluated by: lm(log(PK) ~ sequence+subject+period+treatment, data=study)
              PE.AUC[study]  <- exp(summary(model.AUC)$coef["treatmentT", "Estimate"])
              PE.Cmax[study] <- exp(summary(model.Cmax)$coef["treatmentT", "Estimate"])
              pearson <- cor.test(PE.Cmax, PE.AUC)
              rho     <- pearson$estimate
              CI      <- as.numeric(pearson$conf.int)

rho         : 0.6540 (95% CI: 0.5483 … 0.7391)

❝ If I look at the location of your PE's on the horisontal axis (the AUC axis) then it looks to me like there are more points on the higher side of 1 than on the lower side.

cat(sprintf("%.1f%%", 100*sum(PE.AUC > 1)/length(PE.AUC)), ">1\n"); summary(PE.AUC, digits=4)
58.5% >1
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
 0.7206  0.9768  1.0110  1.0250  1.0600  1.2850

❝ Same might apply for the vertical axis, not sure. Perhaps I am only hallewcinating?:-D

❝ Perhaps it is only a graphical artifact?

cat(sprintf("%.1f%%", 100*sum(PE.Cmax > 1)/length(PE.Cmax)), ">1\n"); summary(PE.Cmax, digits=4)
57.7% >1
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
 0.6692  0.9586  1.0320  1.0260  1.0950  1.3800

❝ Or something with the selection of studies plotted?

Duno. In the meantime I removed two studies (one was a tablet vs. a suspension and the other one from Hauschke/Steinijans – two MRs but the target was “flatter is better”) and added a couple more. It was easy to import the data but now I have to check in the protocols what the target was. Not always stated in the title and boring reading matter. Will take a while.

❝ If not, then I wonder why that wold be so? I imagine you don't really have the answer but I am curious about any speculation from your side or from others. My head is already abuzz with stabilities and overages and much other weird stuff from the odd sock drawer of speculation.

You are not alone. I have more questions than answers myself. Most circle around which ones to include:Basic research is what I’m doing
when I don’t know what I’m doing.
    Wernher von Braun

Dif-tor heh smusma 🖖🏼 Довге життя Україна! [image]
Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes

Complete thread:

UA Flag
 Admin contact
23,056 posts in 4,840 threads, 1,641 registered users;
74 visitors (0 registered, 74 guests [including 10 identified bots]).
Forum time: 09:03 CEST (Europe/Vienna)

Everything is trivial, if you know the answer.    Thomas Jaki

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz