Читать книгу Medical Statistics - David Machin - Страница 19

The question of whether one has a representative sample is a typical problem faced by statisticians. For example, it used to be believed that migraine was associated with intelligence, perhaps on the grounds that people who used their brains were more likely to get headaches, but a subsequent population study failed to reveal any social class gradient and, by implication, any association with intelligence. The fallacy arose, perhaps, because intelligent people were more likely than the less intelligent to consult their physician about migraine.

In many studies an investigator will wish to compare patients suffering from a certain disease with healthy (control) subjects. The choice of the appropriate control population is crucial to a correct interpretation of the results. This is discussed further in Chapter 14.