Michael Biggs’ rapid response, submitted to the BMJ Open

Does the GP Patient Survey correctly identity trans and non-binary adults?

Saunders et al. (2023) identify trans and non-binary people—here called ‘transgender’ for
brevity—from the question ‘Is your gender identity the same as the sex you were registered
at birth?’ This question was taken from the 2021 Census of England and Wales, where it
produced numerous implausible results (Biggs 2023). One example is that Newham has a
higher proportion of transgender people than Brighton and Hove. Another is that 1 in 67
Muslims is transgender. My analysis demonstrates that people lacking English proficiency or
educational qualifications are massively overrepresented in the transgender population,
according to the census. The explanation, of course, is that many of these people were
confused by the convoluted question and therefore answered ‘no’ in error.

In the GP Patient Survey used by Saunders et al. (2023), blacks are over four times and
Asians over three times more likely to be classified as transgender than whites. The same
ethnic profile is found in the census results. Yet data on referrals to gender clinics for
children and adults alike show that blacks and Asians are significantly underrepresented.
The disparity between survey responses and clinical referrals requires explanation. The GP
Patient Survey also included a question on religion, and so the authors should disaggregate
their sample by this variable. It will be interesting to see whether Muslims are more likely to
be classified as transgender than respondents with no religion, as they were in the census.
That would provide further evidence that the gender identity question was wrongly
answered by a substantial number of respondents. In sum, the authors must provide some
assurance that their classification of transgender people in the sample has sufficient validity
to warrant their findings.

Biggs M (2023) Gender identity in the 2021 census of England and Wales: what went wrong?
SocArXiv. https://osf.io/preprints/socarxiv/yw45p
Saunders CL, Berner A, Lund J, et al. (2023) Demographic characteristics, long-term health
conditions and healthcare experiences of 6333 trans and non-binary adults in England:
nationally representative evidence from the 2021 GP Patient Survey. BMJ Open 13(2):
e068099. DOI: 10.1136/bmjopen-2022-068099.