INTEROPen Design Decision Matrices (DDMs) Guidance

Audience

The audience of this document are internal NHS Digital programmes and external INTEROPen stakeholders and implementation sites for the FHIR specifications. It is assumed that the reader has a basic understanding of HL7 FHIR and has already read FHIR Curation Guide.

What are the DDMs?

During the FHIR curation process, a variety of design decisions are made, for example, the use of appropriate terminology bindings, such as SNOMED CT. These mapping decisions are recorded in the Design Decision Matrices (DDMs) which are used to then build UK specific FHIR profiles, called CareConnect  profiles.

The INTEROPen board has agreed the following definitions for  UK CareConnect Level 2 and Level 3 profiles. Parent profiles (Level 2) and use case specific profiles (Level 3) e.g. problem lists for inpatient discharge summaries, are produced to support information exchange.

Based on these definitions, there are 2 separate DDMs:

  • Level 3 DDM documents delta between a Use case information model e.g. NEWS2 and Level 2 CareConnect profiles e.g. CareConnect observation .
  • Level 2 DDM documents delta between the FHIR International base resource and Level 2 profiles.

Level 3 DDM Guidance

  • Level 3 DDM is use case specific , so any decisions on Level 2 should not be captured here, they should be documented in the Level 2 DDM.
  • Level 3 DDM must contain all the mandatory elements of the level 2 profiles.
  • The ‘data item’ column in the level 3  DDMs should only contain the data item information relevant to the information model or business requirements. This should not have any FHIR elements/data items.  If a FHIR element/node still needs to be curated for the Use Case but there is no data items in the information model, then this should be marked N/A.
  • The ‘Description’ column has clinical/business definition of the data item from the use case information model, this shouldn’t be a FHIR definition.
  • The ‘Cardinality’  Column has cardinality e.g. 0..* from the information model, this is not the FHIR Cardinality.
  • ‘MRO’ Column has information if the data item is ‘Mandatory’, ‘Required’ or ‘Optional’ as per the information model. This is different from FHIR ‘Required’ which applies to some FHIR Value sets.
  • ‘Values’ Column might have Value sets from the information model or recommended refsets or valusets from SNOMED CT or NHS data dictionary.
  • ‘Notes’  Column is for recording comments and discussion but any Actions should be recorded in the ‘Action Log column’. The design rationale should be recorded in ‘Design rationale’ Column and not in the notes column. Any decisions should be marked as ‘FINAL DECISION’ to indicate that a collective final decision was made by all on the Curation Call. Please don’t use initials for recording comments, always use full names. Please put date time and Authors full name before the notes e.g. 1/11/2018 1545 pm Author: Munish Jokhani
  • In all DDMs, the ‘Action Log’ column, should be used to record and track any actions, and the full name of the action owner should be used along with expected completion date of Action.
  • ‘FHIR Target’ Column is used to record the FHIR element/node to which the data item is mapped to, please use complete path to describe the FHIR target. No notes should be recorded in this field.
  • ‘Extension’ Column is used to indicate either the FHIR target is a new Extension then this is marked as ‘Y’ and if not use ‘N’ for No.
  • ‘DataType’ Column is used to record the FHIR data type e.g. Codeable Concept.
  • ‘Design Rationale’ Column is used to record the thinking behind the ‘Final Decision’, this column should not be used to record general notes or actions.
  • ‘FHIR Target Notes’ Column is used to capture comments on the FHIR target e.g. change in cardinality or any other constraints applied. This should not have general notes and actions.

Level 2 DDM Guidance

  • Level 2 DDM is profile specific to record differences between Level 2 profile and base HL7 FHIR International resources, so any decisions regarding the use cases should be logged in Level 3 DDM.
  • The ‘FHIR Target’ column in the level 2  DDMs should only contain items from FHIR international and any UK specific extensions. This should not have any data items from the use cases.
  • ‘Extension’ Column is used to indicate either the FHIR target is a new Extension then this is marked as ‘Y’ for Yes and if not use ‘N’ for No.
  • ‘FHIR description’ is the definition of the FHIR item/node as per International HL7 FHIR resources , a UK definition should be included for any extensions.
  • The ‘Cardinality’  Column has cardinality e.g. 0..* for the FHIR item/node and this is not the cardinality of any data items from the information model.
  • ‘DataType’ Column is used to record the FHIR data type e.g. Codeable Concept.
  • ‘Binding’ Column describes actual binding used in level 2 profile e.g. required, preferred and also used to document the actual FHIR or SNOMED CT value set information.
  • ‘Design Rationale’ Column is used to record the thinking behind the ‘FInal Decision’ , this column should not be used to record general notes or actions.
  • ‘Guidance Notes’ Column is for recording comments and discussion but any Actions should be recorded in the ‘Action Log column’ . The design rationale should be recorded in ‘Design rationale’ Column and not in the notes column. Any decisions should be marked as ‘FINAL DECISION’ to indicate that a collective final decision was made by all on the Curation Call. Please don’t use initials for recording comments, always use full names. Please put date time and Authors full name before the notes e.g. 1/11/2018 1545 pm Author: Munish Jokhani
  • Action Log’ column, should be used to record and track any actions, and the full name of the action owner should be used along with expected completion date of Action.

Further queries?

If you have further queries on DDMs , please email FHIRcuration@nhs.net .