This section presents some examples of standards for accessing clinical records. Please note that this list is not complete, and other standards and formalisms for accessing clinical records do exist.

Clinical Information Modeling Initiative

The HL7 Clinical Information Modeling Initiative (CIMI) is an HL7 International working group, which aims to improve the interoperability of healthcare systems by providing a shared open library of implementable clinical information models.¹ CIMI clinical models, which are defined using computable formalisms such as the Archetype Definition Language (ADL) and Archetype Modeling Language (AML), are based on a common reference model using a common set of data types. CIMI models also have formal bindings to standard terminologies, including SNOMED CT and LOINC. SNOMED CT has been selected as the primary reference terminology for CIMI's clinical models. A number of CDS efforts within HL7 International are expected to use CIMI clinical models as the basis for referencing clinical data within CDS artifacts. For more information on CIMI please refer to Clinical Information Modeling Initiative (opencimi.org) and Clinical Information Modeling Initiative (HL7 work group).

Quality Information and Clinical Knowledge model

The Quality Improvement Core (QICore) Implementation Guide is a U.S. realm-specific CDS initiative that references a logical model called the Quality Information and Clinical Knowledge (QUICK) model. The QUICK model (which is expected to be aligned with CIMI formalisms) will provide a uniform way for clinical decision support and quality measures in the U.S. to refer to clinical data.² The QUICK logical model is defined as a series of QICore specific FHIR profiles. It provides a way for applications to access data using FHIR interfaces. Several of these QICore profiles have bindings to SNOMED CT value sets in their definition. For example, the Condition model (shown below) binds a 'SNOMED CT Body Structure' value set to the data element 'bodySite'.

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Figure 4.2.1-1: QUICK Conditions model

The QUICK logical model provides the basis upon which the FHIR RESTful interfaces refer to clinical data in a CDS service. For more information on QICore please refer to Quality Improvement Core (QI-Core) Implementation Guide.

Virtual Medical Record

The Virtual Medical Record (vMR) for CDS is an HL7 standard, which describes a standardized “virtual interface” for CDSSs to refer to the data in clinical records. The vMR logical data model is based on the HL7 V3 RIM (Reference Information Model). Developing CDS rules can be time-consuming and costly. Hence, the key goal of the vMR is to provide a simplified common information model upon which sharable CDS resources can be developed.³ To implement the vMR, each EHR system must create a virtual interface that exposes its clinical data in the standardized vMR format, to facilitate shared CDS logic working across multiple EHR systems.⁴ An example of an expression, written in terms of the HL7 vMR, which could be used in a CDS rule, is shown below. This expression asserts that a patient has a condition of 195967001 | Asthma| that has a status of 55561003 | Active| .

Figure 4.2.1-2: vMR expression example

GELLO

GELLO⁵ is an object-oriented programming language that can be used to support access to health record data in CDS. It has been adopted by ANSI and HL7 as a language used in CDS and GELLO Release 2 now part of the HL7 v3 product suite.

GELLO provides a standardized interface and query language for accessing data in health information systems. Expressions can also be defined to compare data values and attributes. These values and attributes can then be used in decision support knowledge resources such as rules and guidelines. GELLO works hand in hand with the Virtual Medical Record (vMR). A major advantage of this approach is that GELLO code can be used in different environments where health data is stored using a variety of formats and technologies.

Using GELLO with the vMR ensures that the code does not alter the physical medical record. It can also be used to answer complex queries and to query a reference terminology such as SNOMED CT. The example screen shot below illustrates how SNOMED CT refinements can be used in a GELLO expression:

Figure 4.2.1-3: GELLO expression using SNOMED CT refinement

For more information about GELLO, please refer to HL7 Version 3 Standard: GELLO, A Common Expression Language, Release 2 or http://gello.org.