A clinical trial where participants are switched from one arm to the other part way through.
In crossover trials, each subject receives both treatments being compared or the treatment and control. Such trials are used for patients who have a stable, usually chronic, condition during both treatment periods.
A clinical trial in which all participants receive both treatments, but at different times. Halfway through the study, one group is switched from the experimental treatment to the control treatment (standard treatment), and the other group is switched from the control to the experimental treatment.