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Full-Text Articles in Applied Statistics
Higher Order C(T, P, S) Crossover Designs, James F. Reed Iii
Higher Order C(T, P, S) Crossover Designs, James F. Reed Iii
Journal of Modern Applied Statistical Methods
A crossover study is a repeated measures design in which each subject is randomly assigned to a sequence of treatments, including at least two treatments. The most damning characteristic of a crossover study is the potential of a carryover effect of one treatment to the next period. To solve the first-order crossover problem characteristic in the classic AB|BA design, the design must be extended. One alternative uses additional treatment sequences in two periods; a second option is to add a third period and repeat one of the treatments. Assuming a traditional model that specifies a first-order carryover effect, this study …
Estimating The Subject By Treatment Interaction In Non-Replicated Crossover Diet Studies, Matthew Kramer, Shirley C. Chen, Sarah K. Gebauer, David J. Baer
Estimating The Subject By Treatment Interaction In Non-Replicated Crossover Diet Studies, Matthew Kramer, Shirley C. Chen, Sarah K. Gebauer, David J. Baer
Conference on Applied Statistics in Agriculture
Researchers in human nutrition commonly refer to the ‘consistent’ diet effect (i.e. the main effect of diet) and an ‘inconsistent’ diet effect (i.e. a subject by diet interaction). However, due to the non-replicated designs of most studies, one can only estimate the first part using ANOVA; the latter (interaction) is confounded with the residual noise. In many diet studies, it appears that subjects do respond differently to the same diet, so the subject by diet interaction may be large. In a search of over 40,000 published human nutrition studies, most using a crossover design, we found that in none was …
Extension Of Grizzle’S Classic Crossover Design, James F. Reed Iii
Extension Of Grizzle’S Classic Crossover Design, James F. Reed Iii
Journal of Modern Applied Statistical Methods
The crossover design compares treatments A and B over two periods using sequences AB and BA (the AB|BA design) and is the classic design most often illustrated and critiqued in textbooks. Other crossover designs have been used but their use is relatively rare and not always well understood. This article introduces alternatives to a randomized two-treatment, two-period crossover study design. One strategy, which is to extend the classic AB|BA by adding a third period to repeat one of the two treatments, has several attractive advantages; an added treatment period may not imply a large additional cost but will allow carryover …