Bioequivalence and Bioavailability Forum • 2-sequence, 2-period, 2-trt crossover design (R, SAS)

2-sequence, 2-period, 2-trt crossover design (R, SAS) [Software]

posted by yjlee168 – Kaohsiung, Taiwan, 2009-08-20 14:02 (5781 d 18:33 ago) – Posting: # 4075
Views: 8,532

Dear Helmut,

❝ Yes, but have you noticed that results for period and treatment are numerically identical?

You're right! I really did NOT notice that part. A typical anova output obtained from bear is shown as follows.

  Dependent Variable: lnAUC0t                                               



Type I SS

Analysis of Variance Table



Response: lnAUC0t

          Df  Sum Sq Mean Sq F value Pr(>F)

seq        1 0.01876 0.01876  0.5138 0.4872

prd        1 0.00789 0.00789  0.2162 0.6503

drug       1 0.04216 0.04216  1.1546 0.3037

seq:subj  12 0.29718 0.02477  0.6782 0.7443

Residuals 12 0.43818 0.03652               



Type III SS

Single term deletions



Model:

lnAUC0t ~ seq + subj:seq + prd + drug

         Df Sum of Sq     RSS     AIC F value  Pr(F)

<none>                  0.438 -84.405               

prd       1     0.008   0.446 -85.905  0.2162 0.6503

drug      1     0.042   0.480 -83.833  1.1546 0.3037

seq:subj 12     0.297   0.735 -93.909  0.6782 0.7443



Tests of Hypothesis for SUBJECT(SEQUENCE) as an error term



Error: subj

          Df   Sum Sq  Mean Sq F value Pr(>F)

prd:drug   1 0.018762 0.018762  0.7576 0.4012

Residuals 12 0.297182 0.024765               



Error: Within

          Df  Sum Sq Mean Sq F value Pr(>F)

prd        1 0.00789 0.00789  0.2162 0.6503

drug       1 0.04216 0.04216  1.1546 0.3037

Residuals 12 0.43818 0.03652               



Intra_subj. CV = 100*sqrt(abs(exp(MSResidual)-1)) = 19.2847 %

Inter_subj. CV = 100*sqrt(abs(exp((MSSubject(seq)-MSResidual)/2)-1)) = 7.6536 %

    MSResidual = 0.03651522 

MSSubject(seq) = 0.02476518

❝ Maybe there’s a mistake in the coding of the dataset (levels?).

The period and drug (treatment) could be coded incorrectly in the dataset.

—
All the best,
-- Yung-jin Lee
bear v2.9.2:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan https://www.pkpd168.com/bear
Download link (updated) -> here

Complete thread:

2-sequence, 2-period, 2-trt crossover design (R, SAS) Pingouinche 2009-08-19 11:39 [Software]
- 2-sequence, 2-period, 2-trt crossover design (R, SAS) Pingouinche 2009-08-19 16:21
  - R, SAS- codes Helmut 2009-08-19 17:05
    - R, SAS- codes Pingouinche 2009-08-19 22:20
      - R, SAS- codes Helmut 2009-08-20 01:12
        
        R, SAS- codes Pingouinche 2009-08-20 09:19
  - 2-sequence, 2-period, 2-trt crossover design (R, SAS) yjlee168 2009-08-19 18:42
    - 2-sequence, 2-period, 2-trt crossover design (R, SAS) Helmut 2009-08-20 01:19
      - 2-sequence, 2-period, 2-trt crossover design (R, SAS)yjlee168 2009-08-20 12:02
  - 2-sequence, 2-period, 2-trt crossover design (R, SAS) yjlee168 2009-08-20 12:17