Some people who responded to a question in the latest census about their gender identity may not have understood what was being asked due to language barriers, the national statistics body has said.
The 2021 census showed that 262,000 people in England and Wales – 0.5% of the population aged 16 and over – reported that their gender identity was different from their sex registered at birth.
It was the first time this voluntary question had been included in the census, which takes place every 10 years.
Following the publication of the census data, concerns were raised by some that the question might have been confusing for people whose first language was not English.
In an update on Wednesday, the Office for National Statistics (ONS) said it had found some patterns in the data “that are consistent with, but do not conclusively demonstrate, some respondents not interpreting the question as intended”.
The organisation said some areas with large ethnic minority populations had a higher rate of trans responses than might have been expected, such as the London Boroughs of Newham and Brent, where more than 1% of those who answered the question identified as having a gender identity different from their sex registered at birth.
The ONS added: “Since ethnicity can be associated with English language proficiency, this suggests that some respondents whose first language was not English or Welsh did not understand the question as intended.”
The findings showed that, of the population in England and Wales who had English (or Welsh in Wales) as their main language, 0.4% were recorded as trans, compared with 1.6% of people who had a different main language.
Of those with a different main language from English (or Welsh in Wales), the trans population made up 1.0% of people who spoke English very well, compared with 2.1% of people who did not speak English at all.
But the body said that, while such findings “may be unexpected, this does not mean they are necessarily wrong”, and that census estimates on gender identity are “broadly consistent” with the best available comparisons, such as the NHS England GP Patient Survey.
The ONS noted that, as the question was also voluntary, it “cannot say whether the census estimates are more likely to be an over-estimate or an under-estimate of the total number of trans people aged over 16 in England and Wales”.
Its director of population statistics, Jen Woolford, said: “We have confidence in our gender identity estimates at a national level; however, there are some patterns in the data that are consistent with – but do not conclusively demonstrate – that some respondents may not have interpreted the question as intended, for example, people with lower English language skills in some areas.
“While these patterns may be unexpected, this does not necessarily mean they are wrong. Some local authorities may attract trans people due to established communities and unexpected patterns can result from correlations between variables, such as younger age profiles in some ethnic groups.
“We have spoken with users of these data, and they recognise that there will be greater levels of uncertainty in our gender identity statistics. We have also released additional information to help them interpret the data at a detailed level. We have made it clear that these should not be used to create alternative estimates of the trans population.
“We cannot ignore that some trans people are likely to be among those who chose not to respond to this voluntary question, so it is not possible to quantify any potential under- or over-estimate among these groups.
“Any expectations of how the transgender population varies over different population subgroups were built on limited evidence – precisely the evidence gap that inclusion of this question on the census was intended to fill.
“We will continue to develop these statistics as part of our programme to develop population and migration statistics, informed by our recent public consultation.”