[Modeling the requirements on routine data of general practitioners from the health-care researcher's point of view with the help of unified modeling langauge (UML)]

Abstract

Background and aims: Health-care research is, besides primary acquired study data, based on data from widely differing secondary sources. In order to link, compare and analyze data sources uniform models and methods are needed. This could be facilitated by a more structured description of requirements, models and methods of health-care research than those currently used. Suitable methods of presentation were sought in an approach to this target and the unified modeling language (UML) identified as a possible alternative.

Methods: Using different tools 3 UML diagrams were created to represent some individual aspects of a scientific use file (SUF): A use case diagram as well as an activity and a class diagram. In the use case diagram we attempted to represent the general use cases of an SUF based on general practitioners routine data. Secondly a class diagram was constructed to visualize the contents and structure of a SUF. Thirdly an activity diagram was developed to graphically represent the concept of a general practitioner's episode of care.

Results: The creation of the UML diagrams was possible without any technical difficulties. Regarding the content the 3 diagrams must still be considered as prototypes. The use case diagram shows possible uses and users of an SUF, e. g. a research worker, industry but also the general practitioner who supplies the data. The class diagram reveals a general data structure that can serve information processes in practice and research. Besides aggregation, possibilities for specialization and generalization are essential elements of the class diagram that can be used meaningfully. The activity diagram for the schematic representation of a general practitioner's episode of care reveals the existence of multiple endpoints of an episode and the possibility to form relationships by means of episodes (diagnosis>therapy).

Conclusion: The constructed diagrams are preliminary results and should be refined in future steps. Use case diagrams enable a rapid overview of the meaning and purpose of a system, in this case an SUF. Class diagrams can help at a professional level to describe relationships between entities (classes/objects) more clearly than with the existing methods of representation. Activity diagrams are successors to classic flow charts. They are complemented appropriately by status diagrams. UML is suitable to uniformly and graphically describe a system (here an SUF) from various points of view. In future, validated UML models will help us to present scientific concepts and results in a more structured form than before and to promote the technological use of these concepts in practice.