| Info |
|---|
In the ODM, there are many instances where one element needs to reference another -- both within the same file and across files within a series of ODM documents. To accomplish this, the target element is given a unique "name" or Object Identifier (OID). All elements that need to reference that target element just can use its the OID to refer to the object. Example: Say Say we have an item definition (ItemDef) called with a Name "Systolic Blood Pressure" . We set the OID attribute of this ItemDef to "SBP". Then any and OID "SYSBP". Any specific instance of that data item (ItemData) can link back to the definition by setting its own ItemOID attribute to "SBPSYSBP". |
The OIDs used have to be unique, but only within certain contexts. The uniqueness rules are:
- OIDs for each element type inside a MetaDataVersion (e.g., ItemGroupDef) must be unique within the scope of that MetaDataVersion.
- It is best practice to make OIDs unique within the entire MetaDataVersion, however it is allowable to use the same OID for different element types if necessary, e.g., an ItemDef may have the same OID as an ItemGroupDef. This is not recommended This can be confusing and should be avoided.
- Elements in a MetaDataVersion may have the same OID as ones in an Included MetaDataVersion. An element in a MetaDataVersion with the same OID as the same element type in an Included MetaDataVersion is interpreted as replacing the earlier definition. See Include.
- MetaDataVersion OIDs must be unique within the containing Study.
- Study OIDs must be unique within the containing ODM.
- User, Location and Signature OIDs must be unique within the containing AdminData.
- Whenever an element uses an OID to reference another element, the referenced element must occur within the same document as the reference or within a prior document in a linked series. Thus, the referenced element can always be found by tracing back through the PriorFileOID links.
...
- You cannot send a reference to an OID value unless that OID value has been defined, either in the current document, or in a prior document within the series.
- If a definition identified by an OID has changed, the change in its definition must be transmitted before or in the document in which the changed definition is referenced.
- A document that initiates a series must contain all definitions that it references.
- A Transactional document must include any supporting definitions that are new or changed relative to its prior document.
- For example, suppose that document B3207 includes references to item definition X, and that a codelist constraint has been added to X since B3207's predecessor document. In that case, B3207 must also include a MetaDataVersion element (with an new OID) containing an updated definition of item X.
| Pagenav2 |
|---|