Status: PUBLIC REVIEW
Commenting period: This recommendation is open for comment. Comments can be made on the Clinical Trials Subgroup’s working Google Doc. The deadline for adding comments is 9 March 2018.
<related-object>, @content-type, @source-type, @source-id, @source-id-type, @document-id, @document-id-type
This recommendation aims to provide clear guidance on tagging Clinical Trial information using JATS XML for machine readability and reuse. This recommendation only applies to clinical trials the paper is reporting on. Any other clinical trial references that are present should remain as URL links in the text and should not be converted to references/citations or a <related-object>.
For the purposes of registration, a clinical trial is any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects on health outcomes. Interventions include but are not restricted to drugs, cells and other biological products, surgical procedures, radiological procedures, devices, behavioural treatments, process-of-care changes, preventive care, etc. (http://www.who.int/topics/clinical_trials/en/)
Clinical trials are identified by a clinical trial number, which is unique within any given registry but not necessarily unique across registries. Therefore, both the registry and the clinical trial number must be provided in order to identify the clinical trial. In the recommendation below we propose to use the source attributes on <related-object> to identify the registry and the document attributes to identify the clinical trial.
Although JATS4R does not involve itself with editorial decision-making, it is recommended that all clinical trials should: 1) be registered in WHO- approved databases, 2) be listed on the WHO International Clinical Trials Registry Platform (ICTRP), and 3) have a Crossref DOI associated with the metadata. Crossref provides an API that contains both pieces of information (DOI and Name) and the JATS4R validator will use this to provide warning messages if registries other than the ones listed by Crossref are used.
- The ICMJE has indicated that clinical trials should be listed at the end of the abstract, a recommendation which was based on requirements of visual appearance, rather than on those of machine-readability or XML. Additionally, the recommendation was made at an earlier time, before there was a need to include so many pieces of additional metadata important to an article. Thus, the ICMJE’s recommendation has not been included as part of the JATS4R recommendation.
- <related-object>. One clinical trial should be tagged per instance of <related-object>. It can appear in the following places: 1) within the abstract in a separate <sec> or <p>, 2) directly in <article-meta>, or 3) within the flow of the text. The value of this tag is not being prescribed here; the determining elements will be defined in the attributes referred to in Recommendations 2 through 7. Thus, content providers are free to populate or structure the information within the tag itself as they need. [[Validator result: ERROR when there is more than one of each of the attributes and related values, or more than one <xref> link ]]
- @content-type. This attribute can be used to define which stage of the trial the publication is reporting on. Because this is intended for content providers submitting linked clinical trial information to Crossref, the values for this attribute must be “pre-results”, “results”, or “post-results”, as defined in the Crossref schema. The presence of this attribute is optional. [[Validator result: If absent, no message. If present, ERROR if the attribute value is not one of “pre-results”, “results”. or “post-results” ]]
- @source-id. This attribute must identify the clinical trial registry. Crossref curates a list of WHO approved registries and assigns them a DOI, so content providers are encouraged to supply the registry DOI or the WHO registry name as the source-id. A list of these names is available at Crossref.
- @source-id-type. This attribute must be used to identify the type of id given in @source-id. The value of this attribute should be “crossref-doi” or “registry-name” for, respectively, a Crossref DOI or a WHO registry name (see Recommendation 3.) [[Validator results: ERROR if the attribute value is “crossref-doi” and @source-id does not contain the Crossref registry DOI (as provided in the Crossref API); WARNING if the attribute value is “registry-name” and @source-id does not contain the registry name (as provided in Crossref API <title>). ]]
- @source-type. This attribute is required and must be used to indicate the kind of source. The value must be “clinical-trials-registry”. [[Validator result: If this attribute’s value is “clinical-trials-registry”, then validate the related-object against this recommendation. ]]
- @document-id. This attribute is required and must hold the clinical trial number as provided on the clinical trial registry. [[Validator result: ERROR if it is missing.]]
- @document-id-type. This attribute is required and must identify the kind of @document-id. The value must be “clinical-trial-number” or “doi”. [[Validator result: ERROR if it is missing; if present, then ERROR if the value is not “clinical-trial-number” or “doi”]]
Example 1: A clinical trial at the end of the abstract in a separate section (Crossref DOI).
<abstract> ... <sec id="abs3-9"> <title>Clinical trial registration</title> <related-object content-type="pre-result" source-type="clinical-trials-registry" source-id="10.18810/clinical-trials-gov" source-id-type="crossref-doi" document-id="NCT02968459" document-id-type="clinical-trial-number" xlink:href="https://clinicaltrials.gov/show/NCT02968459"> This study is registered with ClinicalTrials.gov as NCT02968459. </related-object> </sec> </abstract>
Example 2: A clinical trial in the body of the article (Crossref DOI).
<article-meta> ... <related-object content-type="pre-result" source-type="clinical-trials-registry" source-id="10.18810/isrctn" source-id-type="crossref-doi" document-id="10.1186/ISRCTN98371961" document-id-type="doi" xlink:href="https://www.isrctn.com/ISRCTN98371961"> Clinical Trial Registration: This study is registered with ISRCTN as ISRCTN98371961. </related-object> ... </article-meta>
Example 3: A clinical trial at the end of the abstract in a separate section (listed registry name).
<abstract> ... <sec id="abs3-9"> <title>Clinical trial registration</title> <related-object source-type="clinical-trials-registry" source-id="ClinicalTrials.gov" source-id-type="registry-name" document-id="NCT02968459" document-id-type="clinical-trial-number" xlink:href="https://clinicaltrials.gov/show/NCT02968459"> This study is registered with ClinicalTrials.gov as NCT02968459. </related-object> </sec> </abstract>