Implementing CDS Hooks Communication in an Arden-Syntax-Based Clinical Decision Support Platform

Introduction: Arden Syntax is a Health Level Seven International standard for the development of clinical decision support (CDS) solutions. CDS Hooks is a specification for an interface to call CDS services from an electronic health record. Implementing the CDS Hooks interface into ArdenSuite, an Arden-Syntax-based CDS platform, will further enhance its interoperability with external systems. Methods: The development of this interface consisted of three parts: (1) The RESTful interface defined by CDS Hooks had to be implemented; this included the support of specifically formatted data for the input and output of the CDS functions. (2) The existing FHIR connector had to be adjusted. In CDS Hooks, a FHIR server can be defined for each CDS service call individually. In the current version of the connector, a FHIR server has to be configured in advance to call the CDS service. (3) Additional data points that did not exist previously, such as a description or hook for each CDS service, had to be collected and saved. Results: Basic support of the CDS Hooks API was established in the ArdenSuite and tested. The FHIR connector was adapted. Discussion: The missing parts for full CDS Hooks support were implemented. As a use case, we employed Hepaxpert, an interpretive system for hepatitis serology tests. CDS Hooks defines FHIR as the only data source. ArdenSuite, in contrast, offers the option of various data sources with connectors and extensions.