Based on the draft instance of the new genericized C-CDA “Sex Observation” template and FHIR US Core Patient Sex extension, our understanding is that the new template and extension are replacements for the previous “Birth Sex Observation” template and FHIR US Core Patient Sex extension. This is understood to be for the exclusive purpose of updating the code system to align with the SNOMED-CT vocabulary cited as standard in USCDI. However, and if so, that is not clear in the current drafts. If this is the intent, then that needs to be clarified by (1) deprecating the predecessor C-CDA  “Birth Sex Observation” template and FHIR US Core Patient Birth Sex extension and (2) providing additional implementation guidance clarifying that the new template/extension are a replacement and should start to be continue being used to exchange data previously exchanged with the now deprecated C-CDA “Birth Sex Observation” template and FHIR US Core Patient Sex extension but using new standard codes.

If the intent is for the new template/extension to be additive (i.e., the C-CDA “Birth Sex Observation” template and the FHIR US Core “Patient Birth Sex” extension are not being deprecated) then that implies systems need to be recording and exchanging another sex concept that is not already covered with its own unique template/extension or field. It is unclear what concept that may be. Additionally, this intent would be misaligned with ONC’s stated intent for the USCDI “Sex” data element in the HTI-1 proposed rule where they state “We note that this is presently a change in the name of the element and will have no immediate impact on health IT developers of certified health IT, which will continue to exchange the value of patient's sex they have been historically exchanging using USCDI” (https://www.federalregister.gov/d/2023-07229/p-339). Accordingly, this would be an inappropriate direction to take with the changes.