Electronic Health Records (EHRs) use diverse data entry models to support various clinical use cases. Each model has specific terminology and information structure requirements. To ensure the captured information is interoperable and meaningful beyond its initial use, it is essential to design a comprehensive context representation model.

The table below outlines common approaches to capturing clinical data and highlights the varying methods used to represent contextual information.

Clinical data entry scenarios and context representation challenges

Record Entry Type		Record Entry Examples
Free text entry Accurate interpretation depends on the way each sentence is phrased. Ignoring any part of the text may lead to misinterpretation. Computerized processing may be possible using  and, in some cases, this may be used to generate structured coded data for subsequent reporting and analysis.		Acute . No past history of  or . Hiatus hernia  was diagnosed 5 years ago. Treats  with . Father died of myocardial infarction at age 57. . Says their cousin has chest problems but is not sure if this is Asthma. Working diagnosis possible myocardial infarction but maybe reflux gastritis. Diagnosis of myocardial infarction.
Structured form with headed sections Accurate interpretation depends on the section heading and the terms or phrases entered under that heading. Computerized interpretation is possible if the meanings represented by the section headings and the terms under each heading are represented using appropriate codes.		Presenting Symptoms Acute central chest pain Past Medical History No known heart disease or lung disease. Hiatus hernia. Family History Myocardial infarction - father (died of this at age 57). No diabetes mellitus in the family. Not sure about asthma. Differential Diagnosis (on admission) Myocardial infarction Reflux esophagitis Diagnosis (after investigation) Myocardial infarction
Structured form with headed sections and prompts for specific data items Accurate interpretation of the meaning depends on the section heading, the question or data label, and the responses or values entered. Computerized interpretation is possible if the meaning represented by the section headings, the specific prompts, and the values selected or entered are represented using appropriate codes and values.		Past Medical History Heart disease Yes  No  Lung disease Yes  No Gastrointestinal disease Yes  No  Hiatus hernia Family History Heart disease Yes  No  Unknown Diabetes mellitus Yes  No  Unknown Chronic lung disease Yes  No  Unknown Vital Signs Heart rate 85 /min Respiratory rate 24 /min Temperature 37.2 C Diagnosis (on admission) Myocardial infarction Confirmed  Possible  Excluded Reflux esophagitis Confirmed  Possible  Excluded Diagnosis (after investigation) Myocardial infarction Confirmed  Possible  Excluded Reflux esophagitis Confirmed  Possible  Excluded

An EHR may be structured in ways that enable data collection and display in structures that emulate the preexisting paper-based record structures. However, there is a significant difference between the structure of a paper record entry and the structure of an electronic record. The structure in which a paper record is stored and displayed is determined by the way the entry was written. In contrast, data entered in an  through different user interfaces may be stored in a common logical data structure. Provided that the logical structure contains the necessary data, the record can be displayed, reported, and analyzed in different ways. This means that different data entry techniques may be appropriate in different situations. For example, in some situations, a fixed checklist of key questions about broadly relevant items of past medical history and family history may be appropriate. In other situations, a more complete and detailed approach appropriate to a specific diagnosis may be preferable. In a paper-based record, these different approaches lead to records with different structures containing similar information. However, as illustrated in , a well-designed electronic health record system can store similar information in a common form even if it is collected through different user interfaces. 

Accurate interpretation of clinical data entered in different ways requires the EHR system to capture, and consistently interpret, information associated with the context in which data is entered. For example, to clearly distinguish between a confirmed diagnosis, possible diagnosis, past medical history, or family history of a disorder. Techniques that can be used to meet this requirement are discussed in the next section 4.2 Health Record Context.

Example of Mapping from Different User Interface Examples to a Common Data Structure