The way information is captured in the clinical record can differ between systems. The choice of Concepts and their representation in the record has implication for interpretation and retrieval.

Requirements for data retrieval are an important determinant of requirements for data content and representation, and the following two overall guidelines can be used to govern the Concept selection and representation:

• To support effective reuse a health record must make it possible to answer relevant questions accurately and efficiently;
• To answer relevant questions information must be selectively retrieved so it can be displayed or analysed.

As the following examples illustrate, the same information (clinical meaning) may be captured in different ways. If information is represented according to the way it is captured it may be difficult to answer simple questions.

A question such as 'does the patient have a family history of diabetes mellitus?' can expand to:

1. 1. Do they have a family history form in which 'diabetes mellitus' is checked as present?
   2. Do they have a family history record in which the code for 'FH diabetes mellitus' is present?
   3. Do they have text that is tagged with the code for 'diabetes mellitus' in the context of a section of text tagged as 'family history'?

… n. There are many other data capture representations to consider