Design and evaluation of a temporal, graph-based language for querying collections of patient histories

Giving clinicians and researchers the ability to easily retrieve and explore relevant fragments of patient histories would greatly facilitate quality assurance, patient followup and research on patient treatment processes. Established database query languages are inconvenient for such exploration, and may also be too complex for users with limited backgrounds in informatics. We believe that understandability can be increased in return for a sacrifice of some of the power of expression found in general query languages. In order to design a specialized query language, we have collected and synthesized a tentative list of requirements. Based on these requirements, we have designed and implemented Practice Explorer, a prototype for visual query of collections of patient histories, and evaluated the understandability of its query language by testing with medical students. The results indicate that parts of the language are intuitive enough for users to understand without demonstrations, examples, feedback or assistance. They also provide some lessons for future work in this area.