To exchange and interpret clinical information consistently between electronic health record (EHR) systems, the data structures used to represent distinct items of information need to be standardized [1], [2], [3], [4], [5]. These data structure definitions, known as detailed clinical models (DCMs), specify how a particular kind of entry within an EHR has to be organized, for example, which clinical terms apply, what value range is valid, which measurement units may be used, which data items within the structure require a value [6], [7]. The clinical element model by Intermountain Healthcare [8], [9], templates defined by HL7 International [10], [11], archetypes defined by the openEHR Foundation [12], [13] and ISO 13606, the Clinical Information Model in the Netherlands [14], and the Clinical Content Model by the Center for Interoperable EHR in South Korea [15] are examples of published DCM formalisms that can be used to organize the clinical content of an EHR interoperability message and an EHR repository, share decision logic, and build a data capture form of a clinical application. Each instance of a DCM dictates how a corresponding generic EHR representation is to be used to represent particular types of clinical information. Examples of DCM instances might include representations for documenting a pain symptom, heart sounds, liver function tests, a prescribed drug, or a chest X-ray report.
Whereas DCMs have the potential to improve clinical decision support and clinical documentation in EHR system, the critical challenge is to identify the qualitative and quantitative requirements of DCMs. A few studies have suggested some quality requirements for DCMs (Table 1). For the flexibility and scalability of DCMs, general requirements for the system in which clinical data models are implemented demand the following [16], [17]: (1) the addition of elements and attributes to the clinical model without the necessity of changing the underlying software or database schema; (2) use an existing formalism/syntax for the representation of the model; (3) tight binding of model attributes to standard terminology systems; and (4) the existence of a mechanism for stating ‘negation’. General principles of good modeling include: (1) adoption of standard terminologies for use in the models; (2) representing the models in standard modeling languages; (3) sharing and approving the DCMs with a community of clinical experts; (4) define decision modules that reference the models. DCM quality criteria [18] have also been proposed where the following qualities were identified as being important requirements of a good DCM: usefulness, desirability, the degree of use/acceptance in clinical services, reusability, the quality of clinical content, the degree of clinician introduction/validation, the use of vocabulary, mapping to information models, applicability, application to other technologies, and maintenance.
Principles for the development of DCMs [19] can be classified as principles pertaining to the structure of the DCM, principles for creating the DCM content, and principles for the DCM development process. The principles that pertain to the structure of DCMs contains information about the language formalism, description of binding of attributes to standard terminologies, a strategy for supporting semantic links among DCM instances, the definition of standard data types, and the description of standard units of measure. The principles for DCM content creation emphasize the granularity, reusability, correctness, and comprehensiveness of the models. Principles for the DCM development process emphasize evidence based model development, the need for proper use cases, use of meta data to track changes, and compliance to the syntax of the modeling language.
Archetype representation requirements [20] published in ISO 13606-2 are focused more on the technological aspects of models. They are divided into requirements for archetype definition, archetype node constraints, and data value constraints. EuroRec, an organization that certifies EHRs in the European Union, led an EC funded research project to develop criteria for the quality classification of EHR systems [21]. The research resulted in a set of archetype quality criteria, which covered administrative, clinical, technological, information management, and repository operation requirements. Furthermore, they emphasized the use of standard terms and modeling language, the construction of repositories for DCM sharing, and the importance of metadata. Among the clinical requirements, the requirement for clinical use suggests the listing of accurate use patterns of clinical concepts, specification of whether the corresponding archetype is used in a specific workflow, description of subject population groups, as well as expert groups using an archetype, etc.
These published requirements and criteria are valuable sources as a starting place to define the good quality characteristics of DCMs (Table 1). However, these existing quality criteria have different levels of detail. Furthermore, these criteria have not been specified to the level of precision that is needed to undertake formal and objective evaluation of the quality of DCMs. Current DCM criteria cannot compare the quality of DCMs due to the absence of validated and reliable measurable characteristics. There is, therefore, still a need to develop quality metrics that can be used to objectively quantify quality criteria of DCMs.