Your employer says that gender identity is innate.
I am not employed by the NHS. I sometimes do contractual work for them (and sometimes for private providers). They actually say that gender identity is a way to describe a person's innate sense of their own gender. That isn't *quite* the same thing as gender being innate.
The problem for your employer is that on the one hand it has obligations to the WHO and on the other to the UK government, meaning that it is an onerous position. To follow international standards of care it observes the WHO, while at the same time is obliged to follow UK law.
And it doesn't help that both the UK Gov and the WHO use two coding systems that now contradict each other (and both have to be recorded in a sense). To explain this more fully:-
Your doctor has access to a medical EPR which miraculously has ICD-11 on it. They record a diagnosis of Gender Incongruence which would be considered a Sexual Health Condition under ICD-11. The system automatically crossmaps ICD10 and 11 codes to SNOMED CT or offers a browser for the clinician to confirm the SNOMED coding for that condition. The only possible code within SNOMED CT falls under mental health. When the DOH analyse the datasets that they have been sent they will be treating Gender incongruence as a mental health condition.
The NHS no longer collects data from GPs as a data priority item; instead it takes data from how patients Self-ID.
Spoiler - it doesn't. Firstly GP Data comes under the commissioning dataset. The quote you were looking at refers to the Mental Health dataset and the Improving Access to Psychological Therapies Dataset, and so is about recording gender as part of Mental Health care.
But - lets have a look at the Commissioning Dataset TOS (tech spec). Patient characteristics captures person stated gender code. This is now backed up with a second code for "gender identity same at birth indicator".
It doesn't help that the NHS Data Dictionary does not yet contain Gender Identity Code - which just illustrates how disjointed these information resources are. But remember that this code is
only for mental health and IAPT. Not commissioning. Also for current submissions the correct code is person stated gender - gender identity code and the indicator are currently experimental data items.