Interoperability in Healthcare
Interoperability is the ability of diverse systems and organizations to work together (inter-operate). It is defined by IEEE (Institute of Electrical and Electronics Engineers) as “Interoperability is a property of a product or system, whose interfaces are completely understood, to work with other products or systems, present or future, without any restricted access or implementation.” Lack of interoperability between healthcare IT systems is a major problem as pointed out by the PCAST (President’s Council of Advisors on Science and Technology) in its landmark report “Realizing the Full Potential of Health Information Technology to Improve Healthcare for Americans: The Path Forward”. The report states “First, most current health IT systems are proprietary applications that are not easily adopted into the workflow of a clinician’s day, and whose proprietary data formats are not directly exchangeable from one system to another. It is difficult for data to be disaggregated, indexed, searched, and assembled to provide accurate information to treat a patient, because the context for individual entries in a record is often implicit at best.”
The basic purpose for MU (Meaningful Use) incentives is to increase use of interoperable system by the healthcare providers. In this article, we will briefly discuss the need for interoperability in healthcare. We will also look at existing and upcoming standards aimed at increasing this interoperability. Achieving interoperability is no simple matter and involves so many standards that we don’t go very far before it gets too complicated. We will try to clarify how interoperability standards interoperate with each other…
Let us start by looking at two levels of interoperability; Syntactic and Semantic.
· If two or more systems are capable of communicating and exchanging data, they are exhibiting syntactic interoperability. Specified data formats, communication protocols and the like are fundamental. XML or SQL standards are among the tools of syntactic interoperability. This is also true for lower-level data formats, such as ensuring alphabetical characters are stored in a same variation of ASCII or a Unicode format (for English or international text) in all the communicating systems. Syntactical interoperability is a necessary condition for further interoperability.
· Beyond the ability of two or more computer systems to exchange information, semantic interoperability is the ability to automatically interpret the information exchanged meaningfully and accurately in order to produce useful results as defined by the end users of both systems. To achieve semantic interoperability, both sides must refer to a common information exchange reference model. The content of the information exchange requests are unambiguously defined: what is sent is the same as what is understood.
In the recent years, several standards have been developed to increase interoperability (Syntactic as well as Semantic) in healthcare.
· “Direct Project” is one of them. Direct project enables the syntactic interoperability, making sure PHI (Personal Health Information) is exchanged securely.
· “Connect” is an open source application that can be deployed to develop a HIE (Health Information Exchange). This also provides syntactic interoperability.
· HL7’s CCD (Continuity of Care Document) standard is one such standard that offers semantic interoperability.
As mentioned above, we need a common information exchange reference model in order to achieve semantic interoperability. HL7 has developed that reference model. It is called “HL7 Version 3: Reference Information Model” or RIM.
· The RIM is a static model of health and healthcare information as viewed within the scope of HL7 standards development activities.
· The RIM is essential to HL7’s ongoing mission of increasing the precision of data. The RIM became an ANSI-approved standard in late 2003 and was published as an International Organization for Standardization (ISO) standard in September 2006. (Please note that the Reference Information Model is updated on a quarterly basis, with minimal changes through the HL7 harmonization process.)
Achieving semantic interoperability is a challenge for health IT. This is a complex process. For example, a CCD has to be compliant with HITSP (Healthcare Information Technology Standards Panel) C32 and C83 standards which are constraints of HL7’s CCD standard. CCD standards are derived from HL7’s CDA (Clinical Document Architecture) standard. And the CDA standards are based on RIM. In addition to all these standards, we also need to have all the vocabularies required. A developer has to follow through 4 or 5 different documents in order to create a single CCD.
Before moving forward, let us explore the relationship among all these standards that this white paper has mentioned. This is an over simplification at this point. We will explore each of the standards in more depth later.
· The RIM is a large, pictorial representation of the HL7 clinical data (domains) and identifies the life cycle that a message or groups of related messages carry.
· The HL7 Clinical Document Architecture (CDA) is an XML-based markup standard intended to specify the encoding, structure and semantics of clinical documents for exchange. Understanding of RIM is required to understand structure described in CDA standard.
· CCD standard defines what specific information should be conveyed using the CDA structure. CCD establishes a rich set of templates representing the typical sections of a summary record, and expresses these templates as constraints on CDA.
· HITSP has further constrained the CCD with its C32 and C83 standards. For example, CCD allows ICD-9 or SNOMED-CT to be used for recording a ` “Problems List”. C32 constrain the problem list to only SNOMED-CT
· To convey the true meaning of any data, we need to understand the context of that data. For example when we read a sentence, we not only need to know the meaning of each word in the sentence (done by using standard vocabularies) and the grammar (done by using CDA standard) but also the context of that sentence (done by CCD standard) to understand the true meaning.
· CDA, in essence, defines the correct grammar; how different parts of speech come together to make sentences. But what are these “parts of speech”? RIM defines the parts of speech…
Following is a list of some other interoperability standards with a brief overview;
· CCR standard from ASTM
o The CCR standard is a patient health summary standard. It is a way to create flexible documents that contain the most relevant and timely core health information about a patient and sends these electronically from one caregiver to another.
o The Continuity of Care Document (CCD) is an HL7 CDA implementation of the Continuity of Care Record (CCR). A CCR document can generally be converted into CCD using Extensible Style sheet Language Transformations (XSLT), but it is not always possible to perform the inverse transformation, since some CCD features are not supported in CCR.
· C-CDA standard from HL7
o The Consolidated Templated Implementation Guide contains a library of CDA templates dedicated to incorporating and harmonizing previous efforts from Health Level Seven (HL7), integrating the Healthcare Enterprise (IHE) ad Health Information Technology Standards Panel (HITSP).
o It represents harmonization of the HL7 Health Story guides, HITSP C32, related components of IHE Patient Care Coordination (IHE PCC), and Continuity of Care (CCD), and it includes all required CDA templates in Final Rules for Stage 1 Meaningful Use and EHR Certification Criteria 2014 Edition.
· CDAR2 : QRDA standard from HL7
o QRDA (Quality Reporting Document Architecture) is a document format that provides a standard structure with which to report quality measure data to organizations like CMS (Centers for Medicare and Medicaid Services) that will analyze and interpret the data.
o This standard includes a specific QRDA Category I DSTU designed to carry data based on Meaningful Use Stage 2 quality measures expressed in HQMF/eMeasure format.
o Rather than a specific implementation guide for each measure or set of measures, reporting organizations will be able to dynamically generate QRDA instances based on the corresponding eMeasure(s).
· Infobutton Standard by HL7
o The Context-Aware Knowledge Retrieval (Infobutton) and Knowledge Request specification provide a standard mechanism for clinical information systems to submit knowledge requests to knowledge resources.
o Context-aware knowledge retrieval into clinical information systems (CIS), such as electronic health record (EHR) and personal health record (PHR) systems, are an increasingly promising approach for delivering relevant clinical knowledge to the point of care as well as patient-tailored educational material to support patient-centered care. These kinds of knowledge retrieval tools have been known as "Infobuttons."
o For example, an Infobutton displayed in the context of a patient’s problem list may allow a user to view directly educational materials regarding the evaluation and treatment of a specific disease without having to leave the EHR application and look up the knowledge elsewhere.
· Decision Support Services (DSS) by HL7
o A Decision Support Service (DSS) facilitates the delivery of clinical decision support by receiving patient data as the input and returning patient-specific conclusions as the output.
o The HL7 DSS specification provides a standard interface for the provision and consumption of such services. A DSS, for example, can evaluate a patient’s health summary as encoded in an HL7 Version 3 Clinical Document Architecture (CDA®) Continuity of Care Document (CCD®) and provide structured recommendations regarding the patients’ health maintenance and chronic disease management needs.
o The DSS standard defines the collective set of behaviors that one would expect a clinical decision support engine to perform.
o This functionality is required of most healthcare organizations and allows for the data collected in electronic health records and other clinical information systems to provide enhanced value for patients, clinicians, healthcare providers and payers.
o The challenge is that the lack of standards makes the use of decision support services more costly and difficult.
· Arden Syntax for Medical Logic Systems by HL7
o The HL7 International Arden Syntax for Medical Logic Systems is an ANSI-approved American National Standard language for encoding procedural medical knowledge and representing and sharing that knowledge among personnel, information systems and institutions.
o The Arden Syntax assists clinicians, other health care workers and patients to make better decisions through alerts and other information interventions based on logic encoded into health knowledge bases consisting of medical logic modules (MLMs), each of which contains sufficient knowledge to make a single decision.
o With an appropriate computer program (known as an event monitor), MLMs run automatically, generating advice where and when it is needed.
o For example, an MLM can warn clinicians when a patient develops new or worsening kidney failure.
o Arden Syntax is an open standard for representing clinical knowledge, to be used by individual clinicians, institutions and vendors to develop clinical rules (rules that directly affect patient care) using a standard format and language. It is also suited for writing business rules that directly interface with clinical data.
o The Arden Syntax internal programming model is based on declarative logic derived from a multitude of sources (including PASCAL, LISP, APL, PL/1 and HCOM).
· CDS Knowledge Artifact Schema Implementation Guide by ONC
o This implementation guide defines a specification for implementers to use when developing and integrating a Clinical Decision Support (CDS) Knowledge Artifact
o The technical approach adopted is designed to provide a catalog of components to be used in generating knowledge artifacts, with a specific focus on defining the structure of the components and how they work together.
o This implementation guide also focuses not only on structure but also on semantics through the use of standard terminologies, value sets and taxonomies such as SNOMED CT. The specifications will highlight terminology bindings are defined and required.
We will continue our discussion in subsequent papers in this series.
This white paper is compiled by Dr. Qamar Islam, MBBS CPEHR. Dr. Islam is working with Healthy Panacea Network since its inception in 2011. Dr. Islam not only has extensive knowledge of HIPAA, HITECH and Meaningful Use incentives but is also very well versed in industry standards.
To read the PDF file of this white paper, please click here.