Randomized Crossover Experiment
A Randomized Crossover Experiment is a repeated measures randomized experiment that is a crossover experiment (follows a randomized crossover experiment design)
- AKA: Cross-Over Trial.
- Context:
- It can result in Randomized Crossover Experiment Outcome Data that can be analyzed by a Randomized Crossover Experiment Evaluation Task.
- It can range from being a Subject-level Randomized Crossover Experiment to being a Cluster Randomized Crossover Experiment.
- It can range from being a Categorical Outcome Randomized Crossover Experiment to being a Continuous Outcome Randomized Crossover Experiment.
- It can be used for Short-Duration Treatments.
- It can require fewer Experiment Subjects to evaluate than an RCT.
- Example(s):
- Counter-Example(s)
- See: Population Cluster.
References
2013
- http://en.wikipedia.org/wiki/Crossover_study
- A crossover study, also referred to as a 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, education, 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 randomized clinical trial is a repeated measures design, the same measures are collected multiple times for each subject. A crossover clinical trial is a repeated measures design in which each patient is randomly assigned to a sequence of treatments, including at least two treatments (of which one "treatment" may be a standard treatment or a placebo).
Nearly all crossover designs have "balance", which means that all subjects should receive the same number of treatments and that all subjects participate for the same number of periods. In most crossover trials, in fact, each subject receives all treatments.
Statisticians suggest that designs have four periods, a design which allows studies to be truncated to three periods while still enjoying greater efficiency than the two-period design.[1][2] However, the two-period design is often taught in non-statistical textbooks, partly because of its simplicity.
- A crossover study, also referred to as a 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, education, pharmaceutical science, and medicine.
- http://en.wikipedia.org/wiki/Repeated_measures_design#Crossover_studies
- Randomized, controlled, crossover experiments are especially important in health-care. In a randomized clinical trial, the subjects are randomly assigned treatments. When the randomized clinical trial is a repeated measures design, the subjects are randomly assigned to a sequence of treatments. A crossover clinical trial is a repeated-measures design in which each patient is randomly assigned to a sequence of treatments, including at least two treatments (of which one "treatment" may be a standard treatment or a placebo): Thus each patient crosses over from one treatment to another.
2006
- (Turner et al., 2006) ⇒ Rebecca M Turner, Ian R White, and Tim Croudace. (2006). “Analysis of Cluster Randomized Cross-over Trial Data: A Comparison of Methods." Wiley Online Library. doi:10.1002/sim.2537
2003
- (Jones & Kenward, 2003) ⇒ Byron Jones, and Michael G Kenward. (2003). “Design and Analysis of Cross over Trials." CRC Press. ISBN:0412606402
- QUOTE: This book is concerned with a particular sort of comparative trial known as the cross-over trial in which subjects receive different sequences of treatments. Such trials are widely used in clinical and medical research and in other diverse areas such as veterinary science, psychology, sports science and agriculture. … The two-treatment cross-over trials have become increasingly widely used in recent years in bio-equivalence trials. … In a parallel group trial, each experimental unit is randomized to receive one experimental treatment. Such experimental designs are the foundation of much research, particularly in medicine and the health sciences.
1997
- (Pedersen et al, 1997) ⇒ Anette Pedersen, Brittmarie Sandström, and Johan MM Van Amelsvoort. "The effect of ingestion of inulin on blood lipids and gastrointestinal symptoms in healthy females." British Journal of Nutrition 78, no. 02 (1997): 215-222.
- QUOTE: The effect of a daily intake of 14g inulin added to a low-fat spread on fasting blood lipids and gastrointestinal symptoms was investigated in sixty-four young healthy women in a randomized double-blind crossover study involving two periods of 4 weeks. The test spread with and without inulin replaced habitual spread during the test periods. No significant differences between the test periods in plasma total cholesterol, HDL-cholesterol, LDL-cholesterol and triacylglycerol concentrations were observed. Gastrointestinal symptoms assessed with questionnaires showed that in the inulin period there was a significantly (P<0·05) higher degree of discomfort from flatulence and other gastrointestinal symptoms than in the control period. In general, there was no indication of intestinal adaptation to this level of intake of inulin.