The complementary and alternative medicines assessed for the report have been given an effectiveness score of between 1 and 5 and a safety score of green, amber or red.
How was effectiveness measured?
Effectiveness is measured by improvements in:
- general well-being.
Based on the evidence available from clinical trials and other supporting information, each complementary medicine has been put in one of five categories:
- No evidence overall to suggest that the compound works or only a little evidence which is outweighed by much stronger evidence that it doesn’t work.
- Only a little evidence to suggest the compound might work. Evidence often comes from a single study which has reported positive results, so there are important doubts about whether or not it works.
- Some promising evidence to suggest that the compound works. Evidence will be from more than one study but there may also be some studies showing that it doesn’t work, so we’re still uncertain whether compounds in this category work or not.
- Some consistency to the evidence from more than one study to suggest that the compound works. There are still doubts from the evidence that it works, but on balance it’s more likely to be effective than not.
- Consistent evidence across several studies to suggest that this compound is effective.
These classifications are based on the results of studies overall, so a medicine has been classified as effective if:
- a greater proportion of people taking this medicine improved compared with, for example, those taking placebo
- roughly the same proportion of people improved compared to another group taking a conventional drug which is known to be effective.
It doesn’t mean that everyone taking the medicine will improve.
For medicines which we think aren’t effective, the proportion of people reporting improvement when taking these medicines was the same as people taking the placebo, for example.
Sometimes we describe differences in improvement as ‘significant’. This means that we’re fairly sure that the differences between groups didn’t happen just by chance. It doesn’t necessarily mean that the differences are large.
Data is interpreted in this way for conventional medicines – the evidence for conventional treatments doesn’t reach level 5 in all the conditions for which they’re prescribed.
How was safety measured?
We’ve also categorised all compounds according to their safety (assuming that they’re taken within the range of recommended doses – compounds which are well tolerated at the recommended doses may have serious side-effects when taken at higher doses.)
We’ve classified the compounds using a traffic-light system:
Green: Mainly minor and infrequent reported side-effects. Users should check possible side-effects in the product information leaflet.
Amber: Commonly reported side-effects (even if they’re mainly minor symptoms) or more serious side-effects.
Red: Serious reported side-effects. Users should consider carefully before deciding whether to take these medicines.
Some compounds have very little information on side-effects so we’ve not been able to classify them. These compounds have been given an amber rating alongside the statement, ‘No information’.
It’s important to remember that most conventional medicines have side-effects, but we generally have more information to work out what these effects are and how often they happen.
How was the quality of the trial measured?
The quality of RCTs can vary, which affects how reliable the results are. The trials included in the report were judged based on a scoring system called the Jadad scale, which scores from 1 (very poor quality) to 5 (very good quality). To make it easier to use, we’ve collapsed the scale into two categories:
- low quality (Jadad score below 3)
- good/high quality (Jadad score 3 or above).
We’ve marked trials with low quality with the symbol‡. These studies were given a lower weighting when we came to our conclusions.
If you want to read more about this information, we’ve published the following papers:
- Macfarlane GJ, El-Metwally A, De Silva V, Ernst E, Dowds GL, Moots RJ on behalf of the Arthritis Research UK Working Group on Complementary and Alternative Medicines. Evidence for the efficacy of complementary and alternative medicines in the management of rheumatoid arthritis: a systematic review. Rheumatology (Oxford). 2011; 50(9):1672–83.
- De Silva V, El-Metwally A, Ernst E, Lewith G, Macfarlane GJ on behalf of Arthritis Research UK Working Group on Complementary and Alternative Medicines. Evidence for the efficacy of complementary and alternative medicines in the management of osteoarthritis: a systematic review. Rheumatology (Oxford). 2011; 50(5):911–20.
- De Silva V, El-Metwally A, Ernst E, Lewith G, Macfarlane GJ on behalf of Arthritis Research UK Working Group on complementary and alternative medicines. Evidence for the efficacy of complementary and alternative medicines in the management of fibromyalgia: a systematic review. Rheumatology (Oxford). 2010; 49(6):1063–68.