Advantages
A crossover study has two advantages over a non-crossover longitudinal study. First, the influence of confounding covariates is reduced because each crossover patient serves as his or her own control. In a non-crossover study, even randomized, it is often the case that different treatment-groups are found to be unbalanced on some covariates. In a controlled, randomized crossover designs, such imbalances are implausible (unless covariates were to change systematically during the study).
Second, optimal crossover designs are statistically efficient and so require fewer subjects than do non-crossover designs (even other repeated measures designs).
Optimal crossover designs are discussed in the graduate textbook by Jones and Kenward and in the review article by Stufken. Crossover designs are discussed along with more general repeated-measurements designs in the graduate textbook by Vonesh and Chinchilli.
Read more about this topic: Crossover Study
Famous quotes containing the word advantages:
“If we live in the Nineteenth Century, why should we not enjoy the advantages which the Nineteenth Century offers? Why should our life be in any respect provincial?”
—Henry David Thoreau (1817–1862)
“A woman might claim to retain some of the child’s faculties, although very limited and defused, simply because she has not been encouraged to learn methods of thought and develop a disciplined mind. As long as education remains largely induction ignorance will retain these advantages over learning and it is time that women impudently put them to work.”
—Germaine Greer (b. 1939)
“The advantages found in history seem to be of three kinds, as it amuses the fancy, as it improves the understanding, and as it strengthens virtue.”
—David Hume (1711–1776)