Change management and synchronization of local and shared versions of a controlled vocabulary

To share clinical data and to build interoperating computer systems that permit data entry, data retrieval, and data analysis, users and systems at multiple sites must share a common controlled clinical vocabulary (or ontology). However, local sites that adopt a shared vocabulary have local needs, and local-vocabulary maintainers make changes to the local version of that vocabulary. For a local site, there is a tradeoff between having autonomy over a local vocabulary and conforming to a shared vocabulary to obtain the benefits of interoperation. If the local site is motivated to conform, then the burden lies with the local site to manage its own changes and to incorporate the changes of the shared version at periodic intervals. I call this process synchronization. In this dissertation, I present an approach to change management and synchronization of local and shared versions of a controlled vocabulary. This approach supports carefully controlled divergence. I describe the CONCORDIA model, which comprises a structural model, a change model, and a log model to which the shared and local vocabularies conform. I demonstrate use of this model through methods that I have implemented in shared and local versions of a browser and an editor and in a synchronization-support tool. I evaluated my model and methods by performing the synchronization process on a small test set of medical concepts in the subdomain of rickettsial diseases. I obtained content from medical textbooks published at different points in time, and showed evolution of the medical vocabulary in two divergent directions. I synchronized the two versions using the synchronization-support tool. The CONCORDIA model served as an effective approach for representation and communication of vocabulary change.