Correct input data to re-calculate results of 3x3x3 study using lm() [🇷 for BE/BA]

posted by VStus – Poland, 2016-08-27 01:46 (3219 d 17:14 ago) – Posting: # 16600
Views: 6,978

Dear Yung-jin Lee,

❝ So how were the results obtained from running your R codes compared with that from SAS PROC GLM by CRO?


My parameters of interest were: Residuals Mean Squares (MSE), Point Estimate and 90% Confidence Interval. I was able to confirm that these parameters perfectly match with SAS reported values, as well as 'F Values' and 'Pr > F' for prd, drug and seq:subj, but not for seq.

I have regrouped my drug factor to avoid calculation of PE and 90%CI for R/T instead of T/R in some cases:
cat("Available treatments:…")
TotalData$drug["Levels"] ref.drug <- readline(prompt="Enter Reference Treatment Code:  ") #WARNING! No input check!
TotalData$drug <- relevel(TotalData$drug, ref = ref.drug)

By the way, bear's lm.mod() was not confused by having more than 2 periods and 2 sequences, but I've still removed observations for other treatments (T2,T3) from datasets to compare just pair of them. But data was balanced (same number of observations for all sequences).
lm.mod(log(TotalData$C24), TotalData)

Study1:
+----+------------+
|    | P1  P2  P3 |
+----+------------+
| S1 | R   T1  T2 |
| S2 | T1  T2  R  |
| S3 | T2  R   T1 |
+----+------------+
Study2:
+----+----------------+
|    | P1  P2  P3  P4 |
+----+----------------+
| S1 | R   T1  T2  T3 |
| S2 | T1  T2  T3  R  |
| S3 | T2  T3  R   T1 |
| S4 | T3  R   T1  T2 |
+----+----------------+


Best regards,
VStus

Complete thread:

UA Flag
Activity
 Admin contact
23,424 posts in 4,927 threads, 1,674 registered users;
49 visitors (0 registered, 49 guests [including 10 identified bots]).
Forum time: 19:00 CEST (Europe/Vienna)

Complex, statistically improbable things are by their nature
more difficult to explain than
simple, statistically probable things.    Richard Dawkins

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5