(by Elisabeth Spannaus and Julius Hoffmann)
This is a science blog post of two of our students from the Health Information Management seminar taught by members of Care4Saxony. While nowadays in terms of healthcare issues everybody talks about electronic health records, Artificial Intelligence, Machine Learning, Telemedicine etc., one topic, which is often forgotten or at least less publicly discussed, is standards in healthcare.
This rather unglamorous but nonetheless crucial player in healthcare systems is able to extensively improve those. Especially for those fields named before, it is of vital importance to agree upon uniform norms and standards to provide consistent solutions. Therefore, the topic of standardization should be considered, before we talk about further implementations of telemedicine. But what is the current status regarding standardization aspects? In order to shed some light on the topic, existing kinds of standards and some best practice examples that are already in use in Germany, shall be discussed in the following.
First of all, we should also agree on the concept of the term standard, which is “something set up and established by authority as a rule for the measure of quantity, weight, extent, value, or quality” according to the Merriam Webster Dictionary . We get in touch with numerous standards in our everyday life, not necessarily noticing them for what they are – using standardized paper sizes such as A4, wearing a normed t-shirt size or speaking of certain concepts we once agreed upon. While standards do play an enormously important role in everyday life, they nowadays also do in healthcare systems. Well-considered standards provide the foundation for a reliable, functioning, usable, and interoperable healthcare information system . The following brief overview of some current standards in the health care landscape endorses the need for further developments and emphasizes their growing relevance. Especially interoperability, meaning the ability of different systems working seamlessly together, depends directly on deliberate standardization measurements .
To guarantee said efficient interoperability in health care information systems, it is necessary to consider different levels of standards. The first one is the procedural level, where all actions in communication are defined. This includes the declaration of emitters and receivers and whether there is a need to acknowledge the received information. The second level concerns the technical realization of the information exchange. The file format and the inner structure of messages are specified here. These two levels are completed with the semantic standardization, which determines interpretation of the sent data. Depending on the content, there are different semantic standards, e.g. SNOMED CT for nomenclature and ICD to classificate diagnoses . Because of already well-developed and accepted international standards in the first and third level, we are focusing on the technical standards hereafter.
The „E-Health-Gesetz“ in 2015 had a tremendous influence on the sector of electronic healthcare and thus on the existing standards in Germany. The law aims to improve the online message traffic for clinical documents and the storing of medical information, e.g. the medication plan, on a chip card, called „elektronische Gesundheitskarte“ (eGK) . In the course of passing the law, the „Gesellschaft für Telematikanwendungen der Gesundheitskarte“ (gematik) was commissioned to develop „vesta“, a directory for standards in the field of health care information systems. Vesta registers technical and semantic standards, as well as guidelines and profiles . To register a standard, the submitted draft has to be evaluated and accepted by a committee of experts, designated by vesta, and the professional public. The key criterion for the admission is the interoperability with already existing regulations for interoperability .
The register of vesta also contains some standards of Health Level 7 (HL7) . HL7 is an international organization developing standards at the application layer (layer 7) of the OSI model. The objective is to create standards for interoperability, which are optimizing workflows, improving the care delivery and reducing ambiguities .
Yet for many years, the standard HL7 v2 is a big player in Germany for the hospital information system . There are different versions published over the time, the current one is the standard HL7 Version 2.9 . The messages are text files with a clear structure, which depends on the type of message and the trigger event for the message. Every message consists of segments and every segment consists of different fields, which are separated by the pipe symbol (|). The Message Header determines further settings of the message structure and includes the trigger event as well as the type of message. Therefore, the sense of the message is defined by the fields and their position .
In contrast to this rigid structure, the version 3 of HL7 (HL7 v3) is using a different approach. Messages of this standard are in XML format, which means the data elements are arranged via tags in the structure . Thereby, not every message is particularly specified, but rather consists of objects and processes, which are derived by a reference model, called Reference Information Model (RIM). The RIM consists of different basic classes and connection classes. For further application, the model and its classes are getting specified. This method allows a more variable syntax, which means complex scenarios can get depicted in more details, nevertheless it also gets more complicated to implement it into the information system .
Based on the mentioned information model, HL7 developed Clinical Document Architecture (CDA), a standard for the transmission of clinical documents within and between medical institutions. A CDA-document has two parts, the header and the body. The header contains the meta informations of the document and the participants (author and patient), whereas the body contains the proper content, which is structured by general elements, like tables, sections and paragraphs . According to requirements, the body also can contain standardized parts, which could be only narrative text (not interpretable for the computer), but also templates of the RIM for a whole section or single entries of the document . Through these templates the document is not just standardized in terms of the text, but also operable for the computer and therefore enabled for automated processes.
One of the newest standards of HL7 is Fast Healthcare Interoperability Resources (FHIR). This standard aims to support mobile and cloud-based applications and to integrate data of mobile devices. Correspondingly, FHIR is designed like a kit of already defined modules, called resources. Examples for resources are patient, procedure and medication. The resources are linked with others via references and consist of attributes, which are partly already given, if the implementation is likely to use this attribute . Through these standardized components, the interoperability of different systems could get improved over the next years.
While there are standards designed to cover entire information systems, there do also exist some for very delimited fields in healthcare like imaging. A pioneer under all existing standards on the healthcare landscape, regardless of their scope, is undeniably the Digital Imaging and Communication in Medicine Standard (also known as DICOM). Yet in 1985, scientists of the American College of Radiologists started an initiative to connect imaging devices and equipment used in the healthcare setting , which resulted in the definition of the first DICOM. Since then, the protocol was steadily developed further and is nowadays the common data standard regarding digital imaging in healthcare. It truly governs practical digital medicine by offering plenty of advantages like the complete encoding of medical data and a consistent clarity in describing digital imaging devices while providing excellent imaging quality . Contrary to common belief, the guideline is not a communication standard, but an architecture providing interoperability through predefined operations . Specified Syntax and semantics and the determination of what information is needed and what should be documented allow exchanging objects independently of the type of network or storage medium used . Its design seeks an all-encompassing data transfer, storage, and display protocol in order to cover all functional aspects of digital medical imaging . The user is thereby enabled to exchange data independently of the device which was used and of its manufacturer. Furthermore, the standard allows to interconnect different imaging modalities and also imaging modalities with an electronic health record or other health information systems .
Of course, the landscape of existing standards in healthcare from a worldwide perspective is much broader than the presented overview in this blog post. Nevertheless, the post provides a more into detail view and hopefully sensitizes its readers for current problems and obstacles for standards in healthcare. While Germany is not a pioneer in this sector, we may even though conclude that it is on its way to develop better solutions, which are adapted at current healthcare needs. An example is the FHIR, which was discussed beforehand. Its concept, which targets especially interconnect ability on mobile devices, already performs quite good, but there is still the need of some more precise definitions. As for the FHIR, providing interoperability seems to be the key cause for the development of all standards that were discussed. We as a society already agreed upon a vast amount of standards in every other field of human life and interaction, so why should we not further implement this successful concept for health care systems too?