International Patient Summary Implementation Guide
2.0.0 - STU 2

International Patient Summary Implementation Guide, published by HL7 International / Patient Care. This guide is not an authorized publication; it is the continuous build for version 2.0.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhir-ips/ and changes regularly. See the Directory of published versions

## General Principles

Page standards status: Informative

With the formal agreement signed on April 2017, HL7 International and CEN/TC 251 expressed their intent to collaborate under a set of principles for the International Patient Summary (IPS).

Figure 1: The IPS principles

Based on this agreement, the standards specification for the IPS has to be (a) implementable (b) applicable for global use (c) extensible and open to future use cases and solutions. The standards specification and their implementation must be moreover sustainable.

### Context and Usage of Patient Summaries

The IPS defines a patient summary in the context of providing information to downstream providers. These summaries represent coherent snapshots of information for a given purpose at a given time. However its relevance and prevalence make it often considered for other use cases, which can lead to implementation challenges that are not aligned with the principles of IPS or clinical documents generally, mainly the fact that it is a subset of available information. The IPS workgroup is aware of possible caveats and intends to provide additional guidance in future versions.

While profiled sections of the IPS may have content that reflects intentions or orders of clinical care, the IPS is meant as an informative document and is not intended to be directly actionable or machine processable as an order. For example, a MedicationRequest resource in the Medications section or a CarePlan resource in the Plan of Care section, should not be fulfilled or actioned from the IPS document.

### Patient Safety in IPS Context

Patient safety is foundational in healthcare and its importance is even more pronounced in the context of cross-border care information exchange. Understanding specific data elements from IPS profiles is critical to ensuring that clinicians have accurate, timely, and relevant information to make informed decisions. Ignoring or misinterpreting these elements can lead to adverse events.

Elements throughout this IPS guide have obligations for both Creators and Consumers of IPS documents, many of which impact patient safety. Elements flagged with "Is-modifier" (shown as "?!") or those with a SHALL:handle obligation cannot be safely ignored in patient summary sharing. Implementers that are developing IPS consuming functions, either viewers or services that use the information in the IPS need to pay careful attention to obligations and "Is-modifier" flags. Many IPS documents will not populate the elements, particularly in a testing context, but when these elements are populated, or have unusual values, it is important that the clinical facts they convey are understood. Experience gained from the IPS development process has demonstrated that they are easily missed.

Here are some examples of clinical safety cases where ignoring data may introduce patient risk to downstream care:

- The IPS includes an allergy (AllergyIntolerance) where the reaction "severity" (an element with SHALL:handle obligations) is severe
- The IPS includes an immunization (Immunization) where the "occurenceDateTime" (an element with SHALL:handle obligation) is so old that immunity is no longer conferred
- The IPS includes a problem (Condition) which the "verificationStatus" (an is-Modifier) is "refuted", meaning that the problem has been ruled out
- The IPS includes a medication (MedicationRequest or MedicationStatus) where the "status" (an is-Modifier) is "stopped"
- The IPS includes a lab result (Observation) where the "status" (an is-Modifier) is "preliminary", meaning this result may be incomplete or unverified

While this specification does not precisely define how downstream consumers should manage these elements, it is often recommended these elements be available for human-review (often shown as an obligation of SHOULD:display). Of course, language translation and presentation of textual narrative also have implications for patient safety as described with the Design Conventions of the guide. The above highlights on is-Modifier flags and obligations are indicators of some critical elements for safe and effective clinical care.

Ultimately, patient safety benefits from consistent, accurate, and context-aware handling of IPS documents. Creators and consumers of IPS documents should be aware that all data may impact patient safety.

### Structuring Terminology Choices

The IPS is specified in this guide as a HL7 FHIR document (a `Bundle` including an IPS `Composition`), composed by a set of potentially reusable "minimal" data blocks (the IPS profiles). A HL7 CDA R2 representation is also specified in a distinct Implementation Guide. The expressiveness of SNOMED CT and other primary terminologies included in this guide enable the specification to represent information independent of the underlying syntax (CDA R2 or FHIR).

To be universally exchangeable and understood, a patient summary must rely as much as possible on structured data and multilingual international reference terminologies that are licensed at no cost for global use in the International Patient Summary. In the case of SNOMED CT, SNOMED International has created the IPS Terminology, which is an open and free sub-ontology of SNOMED CT that references a core set of clinical concepts licensed at no-cost with the aim to serve the public good. This sub-ontology is maintained in collaboration with HL7 International and other standards development organizations and updated annually. In this spirit, this version of the International Patient Summary defines SNOMED CT as a primary terminology and it is used in many of the value sets.

> The IPS value sets that use SNOMED CT content are defined using FHIR inclusion and exclusion criteria. While not used computably in this implementation guide, equivalent Expression Constraint Language (ECL) queries are also shown which may alternatively be used to implement these value set definitions (with a terminology server that supports ECL).
> These value set definitions can be expanded against any available SNOMED CT content. For those in non-SNOMED International Member countries or those without a SNOMED CT Affiliate License, the value set definitions may be expanded against the IPS Terminology, which, as noted above, includes a collection of SNOMED CT concepts that are freely available. For those in Member countries or with a SNOMED CT Affiliate license, the value set definitions should be expanded against the International Edition of SNOMED CT or a national SNOMED CT Extension or Edition, depending on the local requirements.
> To support interoperability of IPS content between organizations that use different SNOMED CT value set content, one proposal is to use a "common proximal ancestor" strategy, substituting any local concept with an ancestor that is shared between the exchanging parties - e.g., a concept in the IPS Terminology. This substitution can be performed using an ECL query, and detailed instructions will be available on the SNOMED ECL documentation.

Other primary terminologies used in this specification are LOINC for observations (e.g., laboratory tests) and document sections, UCUM for units of measure, and ISO 3166 for countries [this ISO code system can be used for free in «lists» (e.g. value sets) or software]. EDQM Standard Terms is also offered as an additional binding which may be chosen as an alternative code system for representing medication dose forms and routes. Looking at the availability of other globally usable reference terminologies, in selected cases FHIR-defined terminologies are recommended.

### Publishing or Accessing the IPS

As described in the IPS CDA implementation guide, it is not in the scope of this IPS FHIR Implementation Guide to constrain solutions or strategies for the creation, sharing, syntactical and semantic mapping, translation, and use of the IPS. Recommendations on operations for IPS generation are included in this guide, although future implementation guides may provide alternative methods and further recommendations different than those outlined. Related HL7 publications, such as International Patient Access, are discussed in Dependencies and Related Guides. In addition, Integrating the Healthcare Enterprise (IHE) has also published guidance on the IHE Sharing of IPS (sIPS), which may be a helpful reference.