J Altern Complement Med. 2000 Jun; 6(3): 253-6.

How to evaluate the effectiveness of complementary therapies.

Linde K.

M�nchener Modell-Center for Complementary Medicine Research, Department of Internal Medicine II, Technische Universit�t, Munich, Germany. [email protected]

The most important question about any treatment is whether it is effective. This article summarizes basic theoretic and practical aspects that are relevant to the evaluation of the effectiveness of a treatment. The factors that can explain why patients improve over time and the ways to separate these factors are outlined. It is explained why, theoretically, randomized clinical trials are the best method to answer questions about effectiveness. Reasons that such trials sometimes fail in practice to provide valid answers are listed. It is argued why evidence from randomized trials must be "complemented" by a variety of different research methods and quality assurance projects.