Though the effectiveness of many treatments varies widely across individuals, treatments are rarely rigorously evaluated on a personal basis. Instead, pressed for time, physicians rely on trial and error testing. But protocols for personal experiments are simple, and their benefits are well documented.
Because many treatments’ effects vary depending on the individual, some researchers argue that effectiveness should be evaluated per patient. Yet a simple evaluation protocol that’s been tested and refined for 30 years, called an n-of-1 trial, is rarely used. Why?