Representing a concept as a folder and a leaf
Sometimes it is necessary to represent a concept as a folder and a leaf, because the folder used for subsumption is also a valid code itself. One example is ICD-10 for coding diseases and diagnoses:
To be able to query such fact in i2b2, you need an extra leaf even if this is a defeat with regards to usability.
i2b2 has no support for multi-axial hierarchies. This causes problems for a number of post-coordinated knowledge organisation organization systems.
In this case, you need to define redundant sub-hierarchies, one for each parent of the current node.
i2b2 ontologies are not made for user and rights management. It is not possiable possible to hide or disable parts of the navigation based on the rights of an a user account. Every folder or leaf is visible and selectable for querying to everyone.