Many of these lead compounds will have toxic effects that are only detected after several months or years of efficacy studies.

Studies that test common factors theory tend to investigate possible differences in outcomes in psychotherapy efficacy studies, and the nature of the approaches being compared.

For the efficacy studies to determine whether acupuncture has specific effects, sham forms of acupuncture seem the most acceptable method for a control group.

Efficacy studies, which are conducted using randomized controlled trials, do not transfer very well to real-world effectiveness.