Homeopathy for chronic asthma.

Background: Homeopathy involves the use, in dilution, of substances which cause symptoms in their undiluted form. It is one of the most widespread forms of complementary medicines and is also used to treat asthma.
Objectives: The objective of this review was to assess the effects of homeopathy in people with chronic stable asthma.
Search Strategy: We searched the Cochrane Airways Group trials register, the Cochrane Complementary Medicine Field trials register, the Glasgow Homeopathic Hospital database, the Muenchener Modell database and reference lists of articles.
Selection Criteria: Randomised and possibly randomised trials of homeopathy for the treatment of stable chronic asthma, with observation periods of at least one week.
Data Collection and Analysis: Data extraction was done by one reviewer and checked by the second reviewer. Trial quality was assessed by the reviewers.
Main Results: Three trials with a total of 154 people were included. These trials were all placebo-controlled and double-blind, but of variable quality. They used three different homeopathic treatments which precluded quantitative pooling of results. The standardised treatments in these trials are unlikely to represent common homeopathic practice, where treatment tends to be individualised. In one trial, severity of symptoms was lessened in the homeopathy group compared to the placebo group. In another trial, lung function measures and medication use showed improvement in the homeopathy group compared to the placebo group. The third trial found improvement in both the homeopathy and placebo groups, but no difference between the groups.
Reviewer's Conclusions: There is not enough evidence to reliably assess the possible role of homeopathy in asthma. As well as randomised trials, there is a need for observational data to document the different methods of homeopathic prescribing and how patients respond.