estimate(test-ref) in bear [R for BE/BA]

posted by yjlee168 Homepage – Kaohsiung, Taiwan, 2018-12-12 18:58  – Posting: # 19686
Views: 1,732

Dear mittyri & all others,

» » As Yung-jin explained me that PE in R/bear is not a direct arithmetic difference, and it is estimated in a specific linear model in ANOVA.
» Sounds strange to me. Do we have the ratio of LSMeans, the ratio of GeoMeans and something else?:confused:
» Let's wait for Yung-jin's comments

Estimate(test-ref) in bear is not obtained directly from the difference of mean values or lsmean. It is obtained from one of coefficients of lm() function. I cut the outputs from a test run and show it as follows:   
---
 Summary Pivotal Parameters of BE Study 
------------------------------------------
 Dependent Variable: log(Cmax)           
------------------------------------------
        n1(R -> T) = 7
        n2(T -> R) = 7
          N(n1+n2) = 14
    Lower criteria = 80.000 %
    Upper criteria = 125.000 %
          MEAN-ref = 7.32951
         MEAN-test = 7.40146
               MSE = 0.01780339
                SE = 0.05043155
Estimate(test-ref) = 0.07195028

######  testing  ######
Call:
lm(formula = log(Cmax) ~ seq + subj:seq + prd + drug, data = TotalData,
    na.action = na.exclude)

Residuals:
     Min       1Q   Median       3Q      Max
-0.13876 -0.08473  0.00000  0.08473  0.13876

Coefficients: (14 not defined because of singularities)
            Estimate Std. Error t value Pr(>|t|)   
(Intercept)  7.48268    0.10086  74.187   <2e-16 ***
seq2        -0.06357    0.13343  -0.476   0.6423   
prd2        -0.05095    0.05043  -1.010   0.3323   
drug2        0.07195    0.05043   1.427   0.1792   
...
---

please browse "Interpreting regression coefficient in R" for more details (the explanations for the coefficient x32). Does anyone know the name of this coefficient in statistics? Thanks.

All the best,
---Yung-jin Lee
bear v2.8.4:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan http://pkpd.kmu.edu.tw/bear
Download link (updated) -> here

Complete thread:

Activity
 Mix view
Bioequivalence and Bioavailability Forum |  Admin contact
19,478 posts in 4,133 threads, 1,333 registered users;
online 6 (0 registered, 6 guests [including 4 identified bots]).
Forum time (Europe/Vienna): 05:16 CEST

If you don’t know anything about computers,
just remember that they are machines that do exactly what you tell them
but often surprise you in the result.    Richard Dawkins

The BIOEQUIVALENCE / BIOAVAILABILITY FORUM is hosted by
BEBAC Ing. Helmut Schütz
HTML5