11 December 2024  

ONS Letter to the OSR on the GSS workplan towards new harmonised standards for sex and gender identity   

Dear Ed  

I am writing in response to your letter of 12 September 2024 and the final report of Office for Statistics Regulation's (OSR's) review of gender identity estimates for England and Wales from Census 2021 published on the same date. I am pleased to be able to provide an update today on work underway in the Office for National Statistics (ONS) on this important topic. 

Today we are publishing a workplan towards new Government Statistical Service (GSS) harmonised standards for sex and gender identity questions. The workplan sets out how we will develop these standards and guidance, adopting an evidence based development approach utilising Respondent Centred Design (RCD) with its established phases of Discovery, Alpha and Beta activities.

Developing final standards that take into account a range of views and have been rigorously tested is a priority for the ONS. The approach will encompass many of the elements raised in the recommendations for gender identity question development made in the OSR's September report. The RCD process will include engagement with stakeholders to understand the current needs of users and respondents. As well as drawing on the experience of the Census 2021 gender identity question in England and Wales and the trans status and history question in Scotland's 2022 Census, we will be studying international examples. Based on evidence from these stages, prototype questions will be subject to both qualitative and quantitative testing. This development is being undertaken alongside the wider programme of work on the future of population and migration statistics that aims to put administrative data at the core of our statistics production. The work set out in the workplan will include the development of guidance for both the collection of primary research data, and the use of administrative-based data for secondary research purposes. 

The OSR's September 2024 report called on the ONS to consider updating users of the current interim gender identity standard. We have done this today, alongside the publication of the workplan. The previous 'under development' gender identity harmonised standard has been replaced by 'interim guidance' for producers of statistics and researchers who are currently using, or thinking about including, a gender identity question on their surveys or in their administrative data collection. This advises producers to wait for the conclusion of our harmonised standard development process if possible, but provides advice for those needing to use a gender identity or trans status question before that time. The page sets out the gender identity and trans status questions used in Censuses across the UK, alongside additional information and considerations users should take when considering how to ask about this topic in their data collection. 

The OSR's September 2024 report also set out four recommendations relating to guidance for use of the census gender identity statistics. Two of these called on the ONS to communicate clearly the implications of the change to 'official statistics in development' and to address the varying levels of information provided across gender identity publications. In response, in September 2024, across the gender identity bulletins and webpages where data tables can be downloaded, we added a statement that the statistics are 'official statistics in development' and stating that this "reflects their innovative nature and the evolving understanding of measuring gender identity, along with the uncertainty associated with these estimates". The notice also directs users to refer to the Census 2021 sexual orientation and gender identity quality information page, which has also been updated to add further information about the reliability of the estimates.   

In line with the other two guidance recommendations, new analysis is currently being undertaken to provide more detailed information on the uncertainty associated with the Census 2021 gender identity estimates, and guidance on their appropriate use. This will include learning from Scotland's Census 2022, from which further statistics on trans status and history are due to be published in 2025, and will provide use cases with recommendations for appropriate use and limitations in different scenarios. We will continue to engage with the OSR on this research and its planned publication in 2025.  Both the Census 2021 sexual orientation and gender identity quality information page and the gender identity harmonisation interim guidance page will be updated to take account of this new research. 

To provide greater transparency about the work on the harmonised standards, I have published a post on the National Statistical blog outlining for a general readership the work we are undertaking on sex and gender identity in the coming months and years. 

I am copying this letter to Professor Sir Ian Diamond, National Statistician, Alastair McAlpine, Chief Statistician (Scottish Government), Stephanie Howarth, Chief Statistician (Welsh Government), Philip Wales, Chief Executive (Northern Ireland Statistics and Research Agency) and the ONS Statistics Head of Profession Office. 

Yours sincerely,  

Emma Rourke  

Deputy National Statistician, Health, Population and Methods Group | Office for National Statistics