Crossover Clinical Trial

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A Crossover Clinical Trial is a clinical trial that is a crossover experiment (where each patient receives a sequence of different treatments, but the order in which treatments are administrated is randomized).



References

2022a

2022b

2022 CrossDesign Fig2.png
Figure 2: Crossover Design Graph.
Fig. 2 is a graphic representation of crossover trial, group 1 is represented by a dashed line and group 2 is represented by a solid line. On the graph’s top left corner, we see that group 1 receives treatment A first, followed by a washout period that is represented here with a green line, and then group 1 receives treatment B. Group 2 receives treatment B first, followed by a washout period, and then group 2 receives treatment A.

2022c

  • (Wikipedia, 2022) ⇒ https://en.wikipedia.org/wiki/Crossover_study Retrieved:2022-1-16.
    • In medicine, a crossover study or crossover trial is a longitudinal study in which subjects receive a sequence of different treatments (or exposures). While crossover studies can be observational studies, many important crossover studies are controlled experiments, which are discussed in this article. Crossover designs are common for experiments in many scientific disciplines, for example psychology, pharmaceutical science, and medicine.

       Randomized, controlled crossover experiments are especially important in health care. In a randomized clinical trial, the subjects are randomly assigned to different arms of the study which receive different treatments. When the trial has a repeated measures design, the same measures are collected multiple times for each subject. A crossover trial has a repeated measures design in which each patient is assigned to a sequence of two or more treatments, of which one may be a standard treatment or a placebo.

      Nearly all crossover are designed to have "balance", whereby all subjects receive the same number of treatments and participate for the same number of periods. In most crossover trials each subject receives all treatments, in a random order.

      Statisticians suggest that designs should have four periods, which is more efficient than the two-period design, even if the study must be truncated to three periods. Vonesh & Chinchilli (1997) Jones & Kenward (2003) However, the two-period design is often taught in non-statistical textbooks, partly because of its simplicity.

2021

PMC3059315 Fig1.jpeg
Figure 1: Study design. D = day; q12h = every 12 hours; W = week.

2011