Alternative and evidence-based medicine

Testing of efficacy
Many alternative therapies have been tested with varying results. In 2003, a project funded by the CDC identified 208 condition-treatment pairs, of which 58% had been studied by at least one randomized controlled trial (RCT), and 23% had been assessed with a meta-analysis. According a 2005 book by a US Institute of Medicine panel, the number of RCTs focused on CAM has risen dramatically. The book cites Vickers (1998), who found that many of the CAM-related RCTs are in the Cochrane register, but 19% of these trials were not in MEDLINE, and 84% were in conventional medical journals.:133

As of 2005 the Cochrane Library had 145 CAM-related Cochrane systematic reviews and 340 non-Cochrane systematic reviews. An analysis of the conclusions of only the 145 Cochrane reviews was done by two readers. In 83% of the cases, the readers agreed. In the 17% in which they disagreed, a third reader agreed with one of the initial readers to set a rating. These studies found that for CAM, 38.4% concluded positive effect or possibly positive (12.4%) effect, 4.8% concluded no effect, 0.69% concluded harmful effect, and 56.6% concluded insufficient evidence. An assessment of conventional treatments found that 41.3% concluded positive or possibly positive effect, 20% concluded no effect, 8.1% concluded net harmful effects, and 21.3% concluded insufficient evidence. However, the CAM review used the 2004 Cochrane database while the conventional review used the 1998 Cochrane database.[15]:135-136

Most alternative medical treatments are not patentable, which may lead to less research funded by the private sector. Additionally, in most countries alternative treatments (in contrast to pharmaceuticals) can be marketed without any proof of efficacy—also a disincentive for manufacturers to fund scientific research. Some have proposed adopting a prize system to reward medical research. However, public funding for research exists. Increasing the funding for research of alternative medicine techniques was the purpose of the US National Center for Complementary and Alternative Medicine. NCCAM and its predecessor, the Office of Alternative Medicine, have spent more than $1 billion on such research since 1992. The German Federal Institute for Drugs and Medical Devices Commission E has studied many herbal remedies for efficacy.

Some skeptics of alternative practices point out that a person may attribute symptomatic relief to an otherwise ineffective therapy due to the placebo effect, the natural recovery from or the cyclical nature of an illness (the regression fallacy), or the possibility that the person never originally had a true illness.

In the same way as for conventional therapies, drugs, and interventions, it can be difficult to test the efficacy of alternative medicine in clinical trials. In instances where an established, effective, treatment for a condition is already available, the Helsinki Declaration states that withholding such treatment is unethical in most circumstances. Use of standard-of-care treatment in addition to an alternative technique being tested may produce confounded or difficult-to-interpret results.