The CDS Hooks specification describes the RESTful APIs and interactions to integrate Clinical Decision Support (CDS) between CDS Clients (typically Electronic Health Record Systems (EHRs) or other health information systems) and CDS Services.
Services, Clients, and Cards
CDS Hooks is a specification describing how to create and use RESTful APIs to add clinical decision support to health care workflows in existing software like EHRs, patient apps, and backend services.
For example, presenting drug costs transparently to doctors while they are writing prescriptions or assessing the acceptable use of a diagnostic imaging service order are both kinds of things you can build with CDS Hooks.
CDS Services and CDS Clients negotiate the exchange of decision support requests and responses across the RESTful APIs. The framework defines a number of Hooks which are pre-agreements about the minimum data requirements for a pre-defined workflow like viewing a patient record or signing a prescription order.
CDS Clients are applications that are responsible for making the request to a decision support service.
CDS Services are the HTTP APIs that accept requests for decision support made by CDS Clients. Importantly, the specification uses FHIR Resources throughout as a way to exchange clinical data.
Services respond to Client requests with CDS Cards. Cards contain decision support information, suggestions, and SMART application links.
CDS Hooks workflow
A CDS Client is an application that makes requests to a decision support service
A CDS Service is an HTTP API that accepts requests containing patient information and provides decision support responses in the form of CDS Cards
A CDS Card is a specific recommendation or suggestion made to the user of the CDS Client