Understanding the Example Model

  1. Every CDA template is represented as a UML class.
    1. In a CDA implementation guide, every class must be derived from a subclass of the CDA base model
    2. The UML model containing all the different classes is the CDA base model
    3. There is a class for every complex type in the CDA schema.
    4. Every implementation guide needs to be specialized with a specific clinical document.
    5. The purpose of the example UML is to illustrate the basic structures that most every CDA implementation guide has.
  2. Notice that there are subclasses of classes
    1. Every implementation guide takes the CDA model and specializes it for a particular type of clinical document.
    2. Template classes are often times reused
    3. A document also contains sections such as history of present illness, past medical history, review of systems, etc. Each of these sections might be where the physician would include the corresponding information.
    4. These domains are named ending with Section. For example: A History & Physical contains at least one section which could be Past Medical History section.
    5. This will be revisited again when we discuss re-using existing templates.
    6. Keep in mind that CDA is the least restrictive model.
    7. Notice the "Open" headed arrow - denotes a "subclass of" and it denotes which existing template it derives from.
    8. Every implementation guide has at least one template class derive from a Clinical Document.
    9. Notice the "Solid" headed arrow denotes the UML association from one class to another -i.e. the relationship between templates - contains - representing a constraints.
  3. The multiplicity domain in the editor can describe the requirements for each document and the conformance rules
    1. This domain provides information about how many sections the document must contain
    2. The severity of the constraint is described with conformance rules in one of the following ways: SHALL (required) contain, SHOULD (suggested) contain or MAY (allowed) contain a specific section
    3. A problem is constrained for a particular purpose to make it easier to solve
    4. The number in the multiplicity domain denotes the minimum and maximum number of observations.
    5. In the case of 1.*, this denotes that there must be at least one but that it can be multiple.