replicateBE solution with interactions [General Sta­tis­tics]

posted by mittyri  – Russia, 2019-12-23 15:30 (1964 d 22:09 ago) – Posting: # 21020
Views: 9,668

Dear Nastya,

whenever possible use simple solutions, at least till the moment you must dive into mixed models galaxy ;-)

And more: interaction terms are not the same in SAS and R
take a look at method.B implementation inside replicateBE package
I just modified it a bit

library(replicateBE)
library(nlme)
alpha <- 0.05
options(contrasts=c("contr.treatment","contr.poly"))
Dataset <- rds01
Dataset$group<- factor(ifelse(as.numeric(levels(Dataset$subject))[Dataset$subject]<31, 1,2))
modB <- lme(log(PK) ~ sequence + group + sequence:group + period + period%in%group + treatment, random = ~1 | subject, na.action = na.omit, data = Dataset)

EMA.B <- summary(modB)
PE <- EMA.B$tTable["treatmentT", "Value"] # exp(PE) = 1.157275
CI <- exp(PE + c(-1, +1) * qt(1 - alpha, EMA.B$tTable["treatmentT", "DF"]) * EMA.B$tTable["treatmentT", "Std.Error"])
# CI = 1.071136 1.250340

Kind regards,
Mittyri

Complete thread:

UA Flag
Activity
 Admin contact
23,424 posts in 4,927 threads, 1,669 registered users;
109 visitors (0 registered, 109 guests [including 4 identified bots]).
Forum time: 14:39 CEST (Europe/Vienna)

We should not speak so that it is possible
for the audience to understand us,
but so that it is impossible
for them to misunderstand us.    Quintilian

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