Article type
Year
Abstract
Background: Complementary and alternative medical (CAM) therapies are widely used by the general public but often criticized for lacking evidence of efficacy from high quality studies. The Cochrane Library, often considered the best source of high quality systematic reviews of CAM healthcare therapies, contained 145 reviews related to CAM as of March 2004.
Objectives: 1. To identify what Cochrane Reviews reveal about the evidence base for CAM. 2. To examine which CAM therapies have the most Cochrane Reviews and the strongest evidence for effectiveness. 3. To identify which therapies widely used or recognized by the general public, hospitals, or physicians are unsupported by Cochrane Reviews, and which therapies supported by strong evidence remain relatively unused. 4. To discuss efforts being made by the CAM Field to insure the preparation of reviews identified as high priority.
Methods: Manual and electronic searches of The Cochrane Library were conducted to identify reviews covering therapies considered CAM according to the US NIH criteria. Two raters trained in RCT and systematic review methodology assigned all CAM-related Cochrane Reviews to one of six categories: positive effect, possibly positive effect, two active treatments are equal, insufficient/ inconclusive evidence, no effect, or harmful effect [1]. When the two raters differed, a third rater assigned the final classification. The inter-rater agreement between the initial two raters was 83%.
The reviews were classified by therapy type. Therapies with the highest number of reviews and the most positive reviews were identified. Disparities between Cochrane evidence and therapy use by the US general public, physicians, and hospitals were identified.
Results: The largest number of reviews were classified as insufficient evidence (n=82, 56.6%); followed by positive effect (n=36, 24.8%); possibly positive effect (n=18, 12.4%); and no effect (n=7, 4.8%). One each was classified in the other two categories.
Therapies with the highest number of reviews on The Cochrane Library are dietary supplements (non-herbal) (71 reviews), herbals (23), electrical stimulation (eg, transcutaneous electrical nerve stimulation) (11) and acupuncture (10). Three-tenths of acupuncture reviews were positive or possibly positive, as were 4/71 dietary supplement reviews, 16/23 herbal reviews and 5/ 11 electrical stimulation reviews.
Herbal therapies and electrical stimulation are supported by strong evidence but are not widely used in all settings. There are no reviews of meditation, and only three each of massage and chiropractic, all commonly used therapies.
Conclusions: While this exercise suggests strong evidence for the effectiveness of some CAM therapies, further research is required, as demonstrated by the numerous classified as insufficient evidence. Only one review fell into the harmful effect category, suggesting that RCTs of CAM therapies have posed little risk to participants.
Efforts underway to insure preparation of Cochrane Reviews identified as high priority include recruiting reviewers; providing funds to applicants proposing high priority reviews; and converting high priority non-Cochrane reviews to Cochrane Reviews.
References: 1. Rating system based on Ezzo J, Bausell B, Moerman DE, Berman B, Hadhazy V. Reviewing the reviews. How strong is the evidence? How clear are the conclusions? Int J Technol Assess Health Care. 2001; 17(4):457-66.
Objectives: 1. To identify what Cochrane Reviews reveal about the evidence base for CAM. 2. To examine which CAM therapies have the most Cochrane Reviews and the strongest evidence for effectiveness. 3. To identify which therapies widely used or recognized by the general public, hospitals, or physicians are unsupported by Cochrane Reviews, and which therapies supported by strong evidence remain relatively unused. 4. To discuss efforts being made by the CAM Field to insure the preparation of reviews identified as high priority.
Methods: Manual and electronic searches of The Cochrane Library were conducted to identify reviews covering therapies considered CAM according to the US NIH criteria. Two raters trained in RCT and systematic review methodology assigned all CAM-related Cochrane Reviews to one of six categories: positive effect, possibly positive effect, two active treatments are equal, insufficient/ inconclusive evidence, no effect, or harmful effect [1]. When the two raters differed, a third rater assigned the final classification. The inter-rater agreement between the initial two raters was 83%.
The reviews were classified by therapy type. Therapies with the highest number of reviews and the most positive reviews were identified. Disparities between Cochrane evidence and therapy use by the US general public, physicians, and hospitals were identified.
Results: The largest number of reviews were classified as insufficient evidence (n=82, 56.6%); followed by positive effect (n=36, 24.8%); possibly positive effect (n=18, 12.4%); and no effect (n=7, 4.8%). One each was classified in the other two categories.
Therapies with the highest number of reviews on The Cochrane Library are dietary supplements (non-herbal) (71 reviews), herbals (23), electrical stimulation (eg, transcutaneous electrical nerve stimulation) (11) and acupuncture (10). Three-tenths of acupuncture reviews were positive or possibly positive, as were 4/71 dietary supplement reviews, 16/23 herbal reviews and 5/ 11 electrical stimulation reviews.
Herbal therapies and electrical stimulation are supported by strong evidence but are not widely used in all settings. There are no reviews of meditation, and only three each of massage and chiropractic, all commonly used therapies.
Conclusions: While this exercise suggests strong evidence for the effectiveness of some CAM therapies, further research is required, as demonstrated by the numerous classified as insufficient evidence. Only one review fell into the harmful effect category, suggesting that RCTs of CAM therapies have posed little risk to participants.
Efforts underway to insure preparation of Cochrane Reviews identified as high priority include recruiting reviewers; providing funds to applicants proposing high priority reviews; and converting high priority non-Cochrane reviews to Cochrane Reviews.
References: 1. Rating system based on Ezzo J, Bausell B, Moerman DE, Berman B, Hadhazy V. Reviewing the reviews. How strong is the evidence? How clear are the conclusions? Int J Technol Assess Health Care. 2001; 17(4):457-66.