Implementing eMedication in the Swiss Electronic Patient Record

Publication Date: 20.07.2022
Swiss Med Informatics. 2022;(01-2021-SMI):XX-XX

Ligier Quentina, Jimenez Rafaela, Bugnon Benjaminb, Spahni Stéphanea

Service de cybersanté et télémédecine, Hôpitaux Universitaires de Genève (HUG), Suisse

Association CARA, Épalinges, Suisse


A good knowledge of the current medication of a patient is key information and an essential element for the continuity of care. However, it is often not easy for a healthcare professional to get accurate and up-to-date information.
Patients would also benefit from a clear view of their medication with names of effectively dispensed products, summary of the posology and reason for intake. The eMedication service described here is an extension of the Swiss EPR platform, aiming at maintaining the medication information related to a patient – whoever the author of the information is. The architecture and the standards used are briefly described, as well as the implementation of a Proof of Concept which is being realized by the CARA EPR Reference Community.


The patient’s medication is key information for guaranteeing the continuity of care. It is however recognized that a significant amount of emergency situations occurs in relation with “medication problems” – wrong intake, adverse events, incompatibilities with drugs that were not known the patient is taking, etc. Having the knowledge of every medication the patient is taking – whoever introduced them – is therefore a key contribution for reducing such events.

The patient’s medication treatment plan summarizes all information describing the medications a patient is taking. Such information is useful to many actors who have different needs. Its management differs from much other information in the sense that it has many contributors and consumers – prescribers, dispensers but also the patient himself – and evolves continuously over time. Presenting it in an uniformized way increases clarity and safety: for patients by clarifying medications and their posology, for prescribers by providing one additional source of information supporting the medication anamnesis, for pharmacists by providing access to the list of current prescriptions to dispense as well as the current list of medications to facilitate the reconciliation.

Adding support for the eMedication in the Swiss Electronic Patient Record (EPR) [1] will allow for a secondary but common and shared source of information, representing a huge improvement regarding the actual situation where information is dispersed between actors. Important benefits for the quality of therapeutic processes and the patient safety are expected – since unavailable, partial, or unclear information are sources of many emergency admissions to hospital – while simplifying the process for all actors.

The Swiss EPR is organized around interconnected Communities currently implementing a document-based service (EPR XDS). Most but not all communities are Reference Communities, i.e. offer patient enrollment and access. Implementing a global eMedication support is therefore not trivial in such a setting. Following the pilot implementation realized in Geneva’s [2] platform and in a regional pilot project in Canton of Vaud [3], the CARA Reference Community [4] and HUG have decided to join their efforts for implementing and testing in real conditions an eMedication extension to the CARA EPR XDS infrastructure. Results of this Proof of Concept will be analyzed in close collaboration with eHealth-Suisse with the goal to validate the approach and the benefits for patients and healthcare professionals, and eventually of integrating such a service into the national EPR specification.


A shared medication treatment plan is more than a collection of documents: each medication follows a certain workflow, from its introduction in the plan (decision to add the medication to the patient’s treatment plan) until its administration. Being able to present the “current medication treatment plan” results therefore from an aggregation process. The aggregation process will compute the “current state” of each medication, considering every prescription, dispenses and modifications. It is therefore quite different from what a document repository can offer.

To integrate such a process-based service into the EPR, several architectures have been considered and evaluated for their efficiency, easiness to implement and deploy, as well as for other criteria like e.g. completeness of the medication plan and performance. Impact on existing EPR regulation and implementations was also considered: since the medication treatment plan only makes sense as a whole, special rules concerning document access, deletion, deprecation and confidentiality levels management have to be established as current EPR rules are inadequate. Indeed, allowing the patient to e.g. hide a dispense would allow the same medication to be dispensed twice, while hiding one specific medication may lead to risky adverse events.

These various constraints led to exclude a direct use of the EPR XDS infrastructure, which serves primarily as a document repository. Implementing the workflow, considering different access rules and guaranteeing access to all available documents (from every community) would have had too strong an impact on the existing implementations.

Rather than tweaking the EPR XDS service, the eMedication service (management of medication information, aggregation) is proposed as an additional and optional service to which patients must specifically register if they agree with its governing rules. Such a strategy also enables patients to distinguish between medication information and other medical information – a need already expressed by patients, allowing them to differentiate the access granted to various healthcare professionals. A patient may thus for example grant pharmacists access to medication information but not to other medical information (documents).

Considering this, the simplest architecture would be a single, national eMedication service. This is the easiest and cheapest way to develop, deploy and maintain the service while providing the same functionality and quality to all patients and healthcare providers over the country. However, it goes against the spirit of the EPR, where centralization is avoided as much as possible. Moreover, recent events related to centralized services do not plead for such a centralization.

Alternatives imply deploying an eMedication service into each EPR Community. Several variants can be considered here: deployment in reference communities only, or in every community; integrated into EPR XDS platforms or aside but connected service.

The analysis of the pros and cons of the various architectures [5] led us to select a decentralized architecture and opting for a “patient-centric” option: eMedication service is implemented in EPR Reference Communities, and all eMedication information for a patient is managed by a single eMedication service [Figure 1]. This approach differs from the EPR XDS infrastructure, which is healthcare professional centric, i.e. all medication information provided by one healthcare professional is stored into their EPR Community.

Figure 1: 

eMedication Service Architecture

The selected strategy offers multiple advantages, as only one eMedication service is responsible for a specific patient.
Performance, completeness and concurrent access (important to avoid e.g. multiple dispenses of the same prescription in different locations) are easy to guaranty because one single eMedication service has the needed information to perform its tasks. It is also simpler to create and maintain an implementation of the eMedication service as an external, independent system than to implement it in each EPR XDS software platform.

Non reference communities are of course not forgotten. Indeed, primary systems should be able to connect to their community of affiliation for all services provider by the EPR platform. An eMedication service proxy is therefore included in the architecture in order to forward eMedication service requests to the eMedication service of the reference community of the patient.


One keyword of the national EPR infrastructure is “Interoperability”. This sounds perfect with eMedication, where various actors and systems must read and write together in the patient record. In addition, to ensure the highest possible interoperability level, a great emphasis on using already existing, mature and open standards has been placed. The EPR XDS platforms sharing the same requirements with the eMedication service, synergies between existing implementations and the new eMedication service will be simplified.

Interoperability must be implemented at two levels: exchanges (technical) and content exchanged (semantic). Following the standard-based approach, the proposed eMedication service is based on IHE Pharmacy CMPD (Community Medication Prescription and Dispense) profile [6], which describes the various transactions and workflows that have to be implemented when interacting with medication-related repositories. As IHE Pharmacy CMPD is based on IHE XDS and IHE MHD profiles [7], the same basic communication mechanism is used for communicating with the EPR XDS platform and the eMedication service. The RESTful extension based on IHE MHD profile is also fully in line with the forthcoming evolution of the EPR specifications.

In addition to the regular XDS and MHD transactions, two eMedication-specific transactions are introduced by IHE CMPD Profile – one based on XDS and one based on MHD – enabling the retrieval of medication lists. These transactions have been extended through a Swiss national extension to consider national specificities.
Regarding interoperability of the content, it has been decided to keep a document-based strategy in order to stay consistent with the EPR architecture. The most advanced eMedication standard here is IHE Pharmacy’s one, which describes documents for the medication treatment, the prescription and the dispense, as well as advices for updating the current state and medication lists (administration is also available but excluded for the moment for this project). While current IHE Pharmacy profiles are mainly CDA-based, work on FHIR- based profiles is being finalized. CDA-based profiles have been refined under the governance of eHealth-Suisse, resulting in the CDA-CH-EMED national profile [8]. At the same time, HL7 Switzerland has begun work to create an equivalent FHIR-based profile for representing in FHIR the different CDA documents, resulting in the CH-EMED national specification [9]. Indeed, as the transition from one world to the other will take many years, both content profiles will be supported by the eMedication service.

Drugs will be identified by either their GTIN code (which targets a specific package, as used by Swissmedic) or their ATC code (targeting the active ingredients or their category). This gives freedom to prescribers, as they can prescribe a specific package, an active ingredient (e.g. Paracetamol) or even drugs that are not authorized in Switzerland (e.g. Colchicine before the validation of Colctab). In return, implementers will need to support both codes, which can be facilitated by drug databases (such as the Compendium and HCI’s *Index). There may be an incentive for the Federal Office of Public Health to create such a database, accessible to all implementers.

Apart from working with eMedication related documents, the eMedication service has to provide a way to manage access rights. Indeed, as mentioned before, access rules will not be exactly the same as for the EPR XDS, although both are based on the same referential. In order to keep the standards- oriented approach, it has been decided to base the access rights documentation on the IHE APPC (Advanced Patient Privacy Consents) profile, which simply wraps an XACML (eXtensible Access Control Markup Language) content.

XACML is used by the EPR but in a resource-based way where you can add, modify or remove a single rule using a CH:PPQ (Privacy Policy Query) transaction. The choice of a specific management of the access rights is related to access restrictions to the patient’s policies in the EPR XDS platform.


The eMedication service is a strategic project of the CARA EPR Community. Work is in progress along several key aspects:

  • Patient portal;
  • eMedication service;
  • Healthcare providers portal;
  • Integration into clinical information systems.

A collaborative approach is being used in order to have a strong implication of the future users – patients as well as healthcare professionals. They do regularly participate in discussions and workshop to guide the realization of the new service.

A collaborative approach is being used in order to have a strong implication of the future users – patients as well as healthcare professionals. They do regularly participate in discussions and workshop to guide the realization of the new service.

Although core specifications have been established more than one year ago, the complexity of the domain and the rather extensive technical coverage brought to light many unspecified or partially specified aspects in many domains – technical but also organizational and legal ones. Examples are the management of dates (which date is used for what in which situation) or validity of a prescription which is defined at a regional level.

The eMedication service is built around the “eMedication Primary Aggregator” which implements the IHE Pharmacy CMPD profile as well as specific rules. A rather complete prototype of this aggregator is expected in autumn 2022 (preliminary versions were already tested during eHealth- Suisse Projectathons in 2020 and 2021), while the Proof of Concept phase should start beginning of 2023 within CARA EPR Community. Two major hospitals as well as pharmacists and general practitioners should benefit from a deep integration for the PoC.

To increase interoperability and facilitate new developments, part of the eMedication service code has already been released in open-source projects, mostly in the Husky [10] and IPF [11] libraries. More code will be released at a later stage.


Since the eMedication service is the first non document-based service to be built in the EPR infrastructure, there are many legal and technical issues to be solved, but the work on deep integration of HUG’s Health Information System with the EPR platform and the previous Geneva’s experience have brought valuable knowledge on how to properly design such architectures and workflows. To get the most out of this service, importance has been placed on standardization and interoperability. This should lead to improvements in quality and efficiency of the medication processes for all involved actors – patients and healthcare professionals. A joint effort from technical, clinical and policy stakeholders is required to make this happens.

The strong clinical emphasis also makes the project more complex and innovative: indeed, most of existing eMedication infrastructures focus on prescription and dispense only because it is easier to start the work with administrative and logistical data from pharmacies as they have well-structured and organized computing systems for many years. This approach is easier to implement as it is also linked to billing processes. However, the accuracy of such list showed to be very limited as basic treatment change like stopping do not get capture [12]. The “service-to-users” focus of eMedication service is for sure not the easier path, but is frequently seen as a potential “killer-app” for the development of the EPR infrastructure and service, as well as a “game changer” toward safer and more coordinated care.


Electronic Patient Record (EPR), eMedication, medication treatment plan, Integrating the Healthcare Enterprise (IHE).


Quentin Ligier

Service Cybersanté et Télémedecine Hôpitaux

Universitaires de Genève 4 rue


1211 Genève



1. EPR – Electronic Patient Record:

2. nous/Medias/Actualites/MonDossierMedical-rejoint-CARA.html

3. Improving Primary Care Medication Processes by Using Shared Electronic Medication Plans in Switzerland: Lessons Learned From a Participatory Action Research Study. JMIR Vol 5, No 1 (2021).

4. CARA EPR Reference Community:

5. eHealth Suisse: eMedication in the context of the Electronic Patient Record - Implementation Concept, Bern, March 23, 2020. Available at:

6. IHE Pharmacy profiles:

7. IHE IT Infrastructure profiles:

8. CDA-CH-EMED Specification:

9. CH-EMED Specification:



12. Usage and accuracy of medication data from nationwide health information exchange in Quebec, Canada. Journal of the American Medical Informatics Association, Volume 25, Issue 6, June 2018, Pages 722–729

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