gms | German Medical Science

Introduction: Modern mobile technology used for medical purposes allows assessing daily life behavior and quality of life in a new dimension of precision. Parameters derived from such technique can increase treatment quality [1], [2], [3]. Studies in IBD (inflammatory bowel disease) patients show that co-morbidities [4], [5] are associated with the course of the disease, which reflects in changes in activity, movement and sleep quality. Reaction to these changes, measured by sensors and patient reported outcomes (PRO) can change the course of the disease. A System to establish such endpoints was developed for a research project (GUIDE-IBD) [6]. For the patient reported outcome App, a FHIR data structure was developed to store/send collected data, to configure the App according to the study protocol and to define the displayed questionnaires.

State of the art: In 2019, when this project [6] was initiated, the FHIR standard [7] was just starting to get more traction, only two publications [8], [9] showed approaches to Map Research Protocols to FHIR. They showed that there are unmet needs to solve the use case and that it is complex to model the relationships between the different resources and gave hints to solve these problems. Even with the fast developing efforts of the German Medical Informatics Initiative [10], KBV [11], Gematik [12] and HL7 Deutschland [13] there is less experience and work for defining a study protocol and linking to the collected data. The Resource ResearchStudy is still maturity level 1.

Concept: An App was developed to collect PROs during the day-to-day life of the participant by presenting different questionnaire tasks according to the study protocol. FHIR was defined as the data structure for the App. Resources are the main building blocks of FHIR. The Study is described with the ResearchStudy Resource, it holds the general information about the study. Participants are represented by the Patient Resource and are connected to the ResearchStudy using the ResearchSubject Resource. Questionnaires are defined inside the Questionnaire Resource following the Structured Data Capture implementation guide [14] and used to render the filling UI of the App. The filling process stores the answers inside a QuestionnaireResponse Resource. The definition of the study protocol is solved with the PlanDefinition Resource, which specifies only parts of the protocol regarding the app. It schedules the questionnaires to be filled by the participant and the study visits. Sturdy visits are represented by the Encounter Resource. All tasks in the app are calculated from the PlanDefinition and stored as ServiceRequest Resource. The ServiceRequest connects all Resources. The collected data is sent to the backend in an encrypted transactional bundle.

Implementation: The concept was implemented, is currently used and tested in the project [6]. For the implementation of the FHIR components inside the App and to create a basic FHIR server, the HAPI FHIR libraries [15] were used.

Lessons learned: It is a very reduced model which is fulfilling the requirements of the system, for a next iteration with a more detailed study protocol and more data types the model need to be extended.

The authors declare that they have no competing interests.

The authors declare that a positive ethics committee vote has been obtained.