Crossover Studies, An Example of A Repeated Measures Design
A popular repeated-measures design is the crossover study. A crossover study 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 health-care, especially medicine.
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.
Nearly all crossover designs have "balance", which means that all subjects should receive the same number of treaments and that all subjects participate for the same number of periods. In most crossover trials, each subject receives all treatments.
However, many repeated-measures designs are not crossover studies: The longitudinal study of the sequential effects of repeated treatments need not use any "crossover", for example (Vonesh & Chinchilli; Jones & Kenward).
Read more about this topic: Carryover Effect
Other articles related to "repeated, repeated measures designs, designs":
... a brush fire "911 Out on a Limb" October 16, 1993 Millville, Pennsylvania Repeated from Episode 5.24 "Hockey Havoc" March 14, 1992 Plattsburgh, New York Repeated from Episode 5.24 "African Crocodile ...
... is the stylistic scheme in which words derived from the same root are repeated (e.g ... A related stylistic device is antanaclasis, in which the same word is repeated, but each time with a different sense ... In inflected languages polyptoton is the same word being repeated but appearing each time in a different case ...
... patterns the human body can create across a stage by basic repeated movements such as skipping or turning ... She would create an entire performance piece based on one simple combination that would be repeated numerous time but in a different way ... reverses it the same movements would not be repeated as they were initially introduced ...
... In 2007, the show was repeated for the first time on the CITV channel since 2003 ... It was repeated for a one-off repeat one day in the Easter holidays (as a 'Easter Surprise!') ... Over a year later in December 2008, it was repeated again throughout the Christmas holidays till January 2009 ...
... Repeated measures analysis of variance (rANOVA) is one of the most commonly used statistical approaches to repeated measures designs ... With such designs, the repeated-measure factor (the qualitative independent variable) is referred to as the within-subjects factor, while the dependent ...
Famous quotes containing the words design, measures and/or repeated:
“Joe ... you remember I said you wouldn’t be cheated?... Nobody is really. Eventually all things work out. There’s a design in everything.”
—Sidney Buchman (1902–1975)
“Those who, while they disapprove of the character and measures of a government, yield to it their allegiance and support are undoubtedly its most conscientious supporters, and so frequently the most serious obstacles to reform.”
—Henry David Thoreau (1817–1862)
“It is commonly said ... that ridicule is the best test of truth; for that it will not stick where it is not just. I deny it. A truth learned in a certain light, and attacked in certain words, by men of wit and humour, may, and often doth, become ridiculous, at least so far, that the truth is only remembered and repeated for the sake of the ridicule.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)