Page History

...

We are building a Cochrane vocabulary with links to 4 different controlled vocabularies: MedDRA, SNOMED CT, RXNorm, and WHO ATC. Some of the controlled vocabularies that we are using are more relevant to specific sections of the PICO than others. One of them (SNOMED) is a very large and diverse vocabulary that includes many terms that are unlikely to be relevant to our annotations. We have therefore included only selected subsets of this vocabulary.

Vocabularies for P

For age and sex, MeSH ranges and headings are used.

Terms for the  the "Condition"  portion of P are drawn from 2 standard vocabularies - MedDRA and SNOMED CT.   All of the terms from MedDRA are available for P annotation, but only selected subsets of SNOMED have been included.  If you find term in SNOMED that you feel would be applicable for annotation of a Condition, but you cannot access the term in the P part of the PICO-annotator, please flag it as a vocabulary issue so that we can investigate the possibility of adding it (along with related terms from SNOMED CT). 

...

Many interventions (especially at the review level) involve categories of drugs rather than single agents - antibiotics, vitamins, analgesics, etc.  RxNorm only lists individual drugs or drug combinations and has no codes for drug categories. We are therefore only using WHO ATC and SNOMED CT for categories.  See How to understand the WHO structure for details on how this vocabulary is structured. 

Individual drugs

Since both RxNorm and WHO / ATC have terms for individual drugs, either one can be used to annotate a drug intervention.  HoweverHowever, the terms in WHO / ATC are linked to drug categories while the terms in RxNorm are not.  Because of this, a drug with multiple uses may appear more than once in different parts of the WHO / ATC vocabulary tree.   In In cases where there are several options to choose from, for instance one or more WHO ATC codes and an RXNorm code, then it is best to use the most appropriate WHO ATC codes rather than the RxNorm code.  If you are not sure which one to choose, use the RxNorm code.

...

Both RxNorm and WHO/ATC have terms to cover cases in which 2 or more individual drugs are combined into a single formulation (pill, solution, inhaler etc.) so that they can be easily administered together.  It is usually better to ignore these combination terms and simply annotate the individual components using AND. 

...

Terms for all non-drug interventions are drawn from SNOMED CT.  As with P,  we we have included only selected subsets of this vocabulary.  If you find term in SNOMED that you feel would be applicable for annotation of a non-drug intervention, but you cannot access the term in the I or C part of the PICO - annotator, please flag it as a vocabulary issue so that we can investigate the possibility of adding it (along with related terms).

Vocabularies for O 

We were unable to find Originally there was not a controlled vocabulary that fit well for all outcomes.   However, as we gained experience with annotation, we realized However, during the annotation process, it became clear that many of the terms used in the Conditions section of P were also applicable to outcomes.   We have therefore include Therefore, the same controlled vocabulary terms in O that are available in P (MedDRA and portions of SNOMED CT) are now available in Outcomes.

<a href="#com-atlassian-confluence">Back to Top</a>

...