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The Science
Study Identification And Entry
To arrive at the latest and most relevant information currently available, we perform a range of targeted keyword searches and constantly review a number of the most significant research repositories in the world, which in turn host millions of research citations from medical journals and books. Most prominently we tend to search PubMed, PubMed Central, Research Gate, and the Cochrane Library.
You may have had your own experiences with one or all of them. Most likely, the more time you’ve spent on either data platform the more familiar you’ll be with the strengths and limitations of each of them. To make your research experience as efficient and pleasant as possible we continuously build our database isolating their strengths and minimizing their weakness. As a result it is much easier and faster for you to get the specific information that you need to make more informed and ultimately more empowering choices that are relevant for over 240 different patient populations dealing with chronic conditions and symptoms for which cannabinoid-based therapies present a viable therapeutic option. Beyond that of establishing the broader evidence-based scientific context about if cannabis is thought to work, we also highlight the evidence that suggests what type of cannabis is most appropriate and for which kind of patient.
As we identify studies that are missing from and warrant inclusion in CannaKeys, a more detailed review of the study is performed and the relevant data points are entered.
Updating CannaKeys
CannaKeys is updated continuously as studies are identified. Our goal is to present the most comprehensive review of the data possible and aggregate it in the most useful ways. Our goal is to have relevant studies included within 30 days of publication.
The medical conditions, and cannabinoids, terpenes offered as search options in CannaKeys is also under constant review. We collect the science of additional possible search options and when the science develops enough to warrant inclusion, those condition, cannabinoid, or terpenes are added.
Strength of Science Rating
The Strength of Science rating is designed to provide CannaKeys users with a quick reference to the state and quality of the science presented in the medical condition, cannabinoid and terpene search results and the cannabis chemotype for each condition search output. The goal is to give users a quick view to understand, for any given subject searched, how far the science has progressed when considering cannabinoid therapies. The ratings are based on an algorithm that factors in the number of primary studies, studies specifically exploring the search subject in question, the number of primary clinical studies, and the number of double blind placebo-controlled trials.
Strength of Science Rating Criteria
The Strength of Science ratings criteria are as follows:
- No Rating: If the subject searched has no primary studies, the science and direct evidence are lacking and a “No Rating” is applied.
- Very Low: If the subject has less than three clinical studies associated with it and there are less than eleven total primary studies, a “Very Low” strength of science is applied.
- Low: If there are at least three clinical studies for the condition, cannabinoid, or terpene and there are between 10 and 24 primary studies, a “Low” rating is applied. As the clinical guidance is growing, a higher rating is warranted but the overall guidance is still lacking.
- Moderate: If there are 25 or more primary studies and there are 16 or more primary clinical studies, the subject searched warrants a “Moderate” strength of science. The growth of clinical science has begun to provide more specific information but there is still a lack of the highest quality science.
- Strong: If the search subject has had 16 or more Human Trials published and some of them are Double Blind Placebo-controlled trials, the gold standard of research quality, the strength of science reaches a rating of “Strong”.
- Very Strong: If the search yields 20 or more double blind placebo-controlled trials, the strength of science reaches the top rating of “Very Strong”. With double digit studies providing strong clinical guidance, users can quickly see that there are numerous studies to review and contrast.
Cannabis Chemotype Strength of Science Rating
The Chemotype Strength of Science is presented as part of the Medical Condition Dashboard and provides a quick view of the state of the science with regard to cannabis chemotypes: the primary ratio of THC and CBD, for specific conditions. Cannabis flower and products featuring higher THC than CBD are considered Chemotype I. Chemotype II has even amounts of THC and CBD. Chemotype III flower and products have higher CBD than THC. These chemotypes are useful in understanding where patients should start their consideration about which cannabis therapy is right for them with their practitioner. The Chemotype Strength of Science provides a useful quick view of which chemotype has the most high quality guidance for the condition searched, suggesting possible treatment pathways to consider.
The Chemotype Strength of Science has the identical considerations applied to the science as the full medical condition strength of science and the same rating system. Where it differs is that only the primary studies for that condition associated with research on a particular chemotype are presented for each chemotype. Therefore, a user might see a “Low” strength of science for the condition but the chemotypes will have the same or lower ratings due to the fact that there are fewer studies applicable to each chemotype. Some studies are studying the effects of multiple chemotypes for a condition within a single study. For such studies, if all three chemotypes are associated with a study, they would all influence the chemotype strength of science for associated conditions.
Primary and Related Studies
The Primary/Related designation for studies was created as a way to differentiate studies in relation to the four main CannaKeys searches: medical condition, cannabinoid, terpene, and organ system. In short, a study is considered primary in relation to a search subject if its focus is directly on that subject as part of the research methodology. A related study is one that in some way involves the search subject but is not focused on that subject or the component plays a lesser role in the study. This designation is critical because as the science expands and patients and their caregivers look to sort through larger numbers of results, being able to quickly review primary studies that are focused on their search result saves time and provides more useful information.
Primary and Related Study Designations and Uses
Primary designations allow for key dashboard results and searches to be focused on the most relevant and useful information for any search and are utilized in the outputs in some specific ways. In the dashboard, only primary results are shown in the study breakdown for all searches. Additionally, only primary studies are used in the Strength of Science rating in all searches and the Chemotype Strength of Science Chemotype in the medical condition search.
Related studies, while less focused on the search in question, are still important information to associate with the searches and to make available for review. As research expands and specializes, the broader context of more general studies aid in guiding new directions for research and assist practitioners with medical decisions, especially if published data is scarce.
Primary and Related Designation Criteria
The criteria for designating Primary studies is based on a set of factors that vary slightly based on the type of search. The criteria for primary designations for each search type is as follows:
Medical Condition: Medical condition primary studies are determined by the impact of the components studied on the condition searched. A study is considered primary for a medical condition if the first and one or both of the subsequent conditions are met:
- The study explores modulatory (moves beyond symptom management and therapeutically changes the underlying condition) and palliative (addresses symptom management but does not change the underlying pathology) impacts specifically for the condition in question. If the study only explores palliative impacts and is focused on the respective condition, it can still be primary but would be borderline. The specifics studied can be mechanisms related to the condition, particularly if the condition is directly noted.
- The condition is specifically noted in the study title.
- The key findings and conclusions specifically reference the condition in question in a direct way as opposed to a suggestive mention or as part of a list of conditions of possible interest.
Studies that don’t meet the criteria above are considered related if they meet most or all of these criteria.
- If the study mentions the possible therapeutic potential in a less direct way, usually noting a list of conditions that could be considered. This is often seen with more general meta-analyses.
- The study is closely related to a specific condition and mentions the relation somewhere in the study but is not exploring direct palliative or modulatory effects.
- If the condition is mentioned in the title of the study but the design of the study is not targeted on modulatory or even palliative impacts. An example of this includes population studies that explore the prevalence of cannabis use in certain patient populations which is a related but not primary inquiry.
Organ System: The studies returned in the organ system search are a function of the medical conditions flagged as part of each system. For example, the condition Crohn’s Disease is flagged as part of the Digestive System and shows up when that system is searched. The primary and related designations for studies in the organ system search are carried through from the designations at the condition level.
Cannabinoid: The cannabinoid primary studies are determined by the nature of how the cannabinoid (or enzyme or other compound) was examined or utilized in the study. Many cannabinoids can be used in a study but that does not mean that all of them are primary. A study is considered primary for a cannabinoid if two or all three of the following conditions are met:
- The cannabinoid is specifically part of the main inquiry for the study and is at a high enough dose to be understood as influencing the results. This can also mean that if a cannabis extract with multiple cannabinoids present, the primary constituents (more that 20% of the extract) of that extract are considered primary while the minor constituents (5-20%) are associated as related to that study. Trace cannabinoids (under 5%) would not be associated with the study.
- The cannabinoid is mentioned in the study title, particularly noting its efficacy or lack thereof.
- The key findings and conclusions specifically reference the cannabinoid in question as the active agent with regard to study findings.
Studies that don’t meet that criteria detailed above but still note the cannabinoid as part of the study design are considered related if they meet one or both of these criteria.
- As noted above, the cannabinoid is a significant but minor component of a studied extract or other preparation, from 5-20% of the extract.
- The cannabinoid is a small part of the study, often alongside many other cannabinoids. This is often seen with more general meta-analyses which review basic questions or explore efficacy of a wide range of cannabinoids for a specific condition.
Terpene: Terpene primary studies are determined by the nature of how the terpene was examined or utilized in the study. Many terpenes can be used in a study but that does not mean that all of them are primary, usually when an essential oil or plant extract is examined. To-date there is very little data available that determines the amount necessary to produce physiologically observable effects. The limited literature suggests a potential threshold of 0.05% for terpenes to register an effect. While this area continues to be studied, CannaKeys chooses to associate studies where the terpene represents a more substantial percentage of any given oil or extract. A study is considered primary for a terpene if two or all three of the following conditions are met:
- The terpene is specifically part of the main inquiry for the study and is at a high enough dose to be understood as influencing the results. This can also mean that if a cannabis extractive or essential oil with multiple terpenes present, the primary constituents (more that 20% of the extract) of that extract are considered primary while the minor constituents (5-20%) are associated as related to that study. Trace terpenes (under 5%) would not be associated with the study.
- The terpene is mentioned in the study title, particularly noting its efficacy or lack thereof.
- The key findings and conclusions specifically reference the terpene in question as the active agent with regard to study findings.
Studies that don’t meet that criteria detailed above but still note the terpene as part of the study design are considered related if they meet one or both of these criteria.
- As noted above, the terpene is a significant but minor component of a studied extract or other preparation, from 5-20% of the extract.
- The terpene is a small part of the study, often alongside many other terpenes or other compounds. This is often seen with more general meta-analyses which review basic questions or explore efficacy of a wide range of terpenes for a specific condition.