Research into complementary therapies

The types of testing and evidence that form the knowledge bases of many complementary therapies tend to differ from those that form the knowledge bases of conventional Western medicine.

Knowledge based on a collection of individual stories rather than research data is called anecdotal evidence. This information can be collected and shared by practitioners or by the people using the treatments. Anecdotal information is important in complementary medicine, as it is often recorded and compiled to form a base of information about the likely outcome of a treatment. Anecdotal information has limitations. It is often based on a limited set of individual experiences; it is difficult to determine how widely these experiences can be applied across populations.

In Western medicine, treatments are tested before they are used. The current standard for testing a Western medical treatment is a randomized, double-blind, placebo-controlled clinical trial. In this sort of trial a set of participants who all have the same medical condition are divided into two groups. One group receives the real treatment and the other receives a placebo (fake treatment). No one knows who is getting the real treatment. Participants are randomly assigned to one group or the other, to prevent the researchers from selecting which study participants will receive the treatment or placebo. The study is called double-blind because even the physicians and researchers who collect the results are not told which participants received placebo and which ones received the treatment. This method is intended to eliminate biases based on the expectations of the researchers and participants and to gather reliable statistical evidence about how often we can expect the treatment to work.

Some complementary therapies have been and are being tested in randomized, double-blind placebo-controlled trials. However, various factors can make it difficult to conduct clinical trials of complementary therapies, such as the lack of availability of a pure, consistent, controlled dose of the therapy to use in clinical trials, skepticism and a lack of funding for trials.