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 Münchener Modell database and reference lists of articles. Searches were current as of August 2003.
Selection criteria: Randomised trials of homeopathy for the treatment of stable chronic asthma, with observation periods of at least one week were included.
Data collection and analysis: Data extraction was undertaken by two reviewers. Trial quality was assessed by the reviewers.
Main results: Six trials with a total of 556 people were included. These trials were all placebo-controlled and double-blind, but of variable quality. They used different homeopathic treatments which precluded quantitative pooling of results for the primary outcome. Standardised treatments in these trials are unlikely to represent common homeopathic practice, where treatment tends to be individualised. No trial reported a significant difference on validated symptom scales. There were conflicting results in terms of lung function between the studies. There has been only a limited attempt to measure a 'package of care' effect (i.e., the effect of the medication as well as the consultation, which is considered a vital part of individualised homeopathic practice).
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. This will help to establish to what extent people respond to a 'package of care' rather than the homeopathic intervention alone.