Evidence-Based Foundation:
Natural Medicines Comprehensive Database is built strictly on the evidence. Many aspects of medicine are influenced by tradition and beliefs passed from one person to another. This is especially true in the area of natural medicines. Some natural medicines are used due to traditional or folkloric beliefs, and some are the subject of excessive marketing claims or excessive extrapolations from test tube or animal studies.
Natural Medicines Comprehensive Database seeks to not perpetuate age-old beliefs and myths, but to replace these with findings from reliable science. Natural Medicines Comprehensive Database attempts to give users reliable information that answers their practical questions about the use of any product in this Database.
To do this, the researchers and editors seek to find the best available scientific evidence on a daily basis. To gather the scientific data, editors, researchers, and contributors systematically review medical journals from around the world. From these journals, hundreds of articles are reviewed and analyzed. This evidence is analyzed and evaluated using the same standards used to evaluate evidence related to pharmaceuticals. The editors do not follow any different standards for evidence related to pharmaceuticals as for natural products.
Once data are filtered and analyzed, the reliable data providing clinically relevant information is added to product monographs. This does not mean that only flawless studies are analyzed. But it does mean that the data that make it into the Database are scientifically reliable. The higher quality research data carry more weight for addition to the Database and more weight in assigning ratings. When evidence does not exist or is deficient for a particular product, this deficiency is acknowledged with a statement indicating a lack of data. Entries to the Database are subject to the peer-review process.
This approach results in Effectiveness Ratings and Safety Ratings as well as the other sections in each monograph. Each natural product is assigned an Effectiveness Rating based on the quality of the evidence for a given indication. See the table below.
| Effectiveness Rating | Level of Evidence |
|---|---|
| Effective | The product has passed a rigorous scientific review equivalent to a review by the FDA, Health Canada, or other governmental authority and has been found to be effective for a specific indication as an OTC drug, orphan drug, or prescription drug product. |
| Likely Effective | Reputable references generally agree that the product is effective for the given indication, based on two or more randomized, controlled, clinical trials involving several hundred to several thousand patients, giving positive results for clinically relevant endpoints and published in established, refereed journals. |
| Possibly Effective | Reputable references suggest that the product might work for the given indication based on one or more clinical trials giving positive results for clinically relevant endpoints. |
| Possibly Ineffective | Reputable references suggest that the product might not work for the given indication based on one human study giving negative results for clinically relevant end-points. |
| Likely Ineffective | Reputable references generally agree that the product is not effective for the given indication, based on two or more randomized, controlled, clinical trials giving negative results for clinically relevant end-points and published in established, refereed journals. |
| Ineffective | Most reputable references agree that the product is not effective for the given indication, or multiple high-quality studies resulted in negative results; there are no equally reliable human studies offering convincing contradictory data. |
Because a high level of evidence is required for a product to be rated Likely Effective or above, relatively few products achieve this rating.