Draft Guidance: Collecting and reporting data about sex in official statistics


Data on an individual’s sex is a commonly asked for or recorded variable in official statistics. Some producers of statistics are making changes, or considering making changes, to the data they collect and report about sex. This guidance details what producers should consider when collecting and reporting data about sex, to meet the expected standards of trustworthiness, quality and value, as outlined in the Code of Practice for Statistics.

As the regulator of official statistics, it is not for us to define what data about sex are collected across the statistics landscape. The UK statistics landscape is complex, with a variety of different data and statistics being produced. Equally, the needs of people using data and statistics can be extensive and varied. This means there can be valid reasons to produce measures based on different classifications or definitions depending on the question the producers are trying to address through the statistics. Our role is to ensure that statistics serve the public good and meet society’s needs for information; we do this by ensuring statistics producers develop and produce statistics in line with the Code.

Work is underway across the Government Statistical Service (GSS) to develop and support the use of harmonised measures of sex and gender in data collection across government. Some of this work will include guidance on what form of data collection and disaggregation is most appropriate in different circumstances. The Office for Statistics Regulation (OSR) supports this work and will continue to engage with producers as it develops.

OSR’s expectations of producers when collecting and reporting data about sex

As a producer, if you are currently collecting and reporting data on sex or are considering making changes to how you do so, it is important that you do so with clarity, being transparent about the reasons for your judgements and decision making throughout. You should explain to users what and how data are being collected and support the appropriate use of the statistics.

Below we summarise our expectations of producers when collecting and reporting data about sex, under each pillar of the Code.


  • The collection and reporting of statistics about sex should support a legitimate public interest and be done in the least intrusive way. Those producing and releasing statistics should be impartial and independent and demonstrate sound judgement.
  • Producers need to understand what data they can legally collect about an individual’s sex and comply with relevant legislation, as well as considering any relevant nationally- and internationally-endorsed guidelines.
  • The privacy and identity of individuals must be protected at all times during data collection, storage, analysis and reporting. This includes being clear and open with individuals providing information about how their information will be protected, applying relevant security standards to keep data secure and using appropriate disclosure methods when releasing statistics.
  • Producers should understand the public debate on data about sex and ensure their statistics stay relevant to a changing society. This means statistics should be regularly reviewed, with users and other stakeholders involved to help prioritise any development plans. Where producers identify user needs that may be impacted by how data on sex are collected, they should consider how they can meet those needs in their work programme, working collaboratively where appropriate, including with relevant subject experts.


  • Producers need to ensure data and statistics stay relevant to a changing society and are of sufficient quality. This means that the statistics should be based on appropriate data and methods.
  • Producers must have a good understanding of, and clearly explain, the sources of data about sex they are using and how these are collected. This applies to survey and administrative data sources; both the question(s) used, and the way that these are completed (i.e. whether data are self-reported or completed by another individual – an interviewer or an operational official, for example) can influence the exact nature of data collected and whether this is a mixture of sex registered at birth, self-identified sex, lived gender and others.
  • Producers should ensure that data are collected in a respectful way and understand any risks to data quality or survey response when asking for sensitive information from a person.
  • Producers cannot always design or change administrative systems which enable public services to be delivered. But they should seek to understand the systems, including any risks and biases that may arise from the way the systems collect and categorise data.
  • Uncertainty in the source data should be identified and the extent of any impact on or limitations of the statistics should be clearly reported. For data about sex this may be particularly relevant when considering data at smaller sub-group levels.
  • Producers should be clear about definitions or terminology they use, and these should be harmonised to be consistent and coherent with related statistics and data where possible. The terms ‘sex’ and ’gender’ should not be used interchangeably in official statistics.


  • Statistics should meet their intended uses and should inform public debate. To achieve this, producers must seek to understand their whole user base and the questions that users want to be able to answer with their statistics.
  • Where an evolving or new user need has been identified, statisticians should consider whether the data that inform the statistics can and should be enhanced to better capture this information. This could mean, where feasible, seeking to build relationships with external data suppliers so that producers have the opportunities and means to influence data collections. Where a user need cannot currently be met, producers should explain why this is the case, and anything that can be done to help these users.
  • Decisions about whether to continue, discontinue or adapt statistics about sex should be made in discussion with users and other stakeholders. If a change is made to data collection, or if information about a data collection practice emerges which makes it clear that the nature of the data may have been previously misunderstood, a clear explanation of the change should be published, with evidence of the rationale and, wherever possible, the analysis that informed the change.
  • Collection and reporting of data about sex is a sensitive and potentially divisive topic and there may be times when producers are unable to meet the requests of everyone who has an interest in their statistics. In these cases, it is more important than ever to be transparent and open about the decision-making process and the evidence used to inform the choices that have been made, particularly in relation to any areas of contention.

A worked example: recording and reporting of sex in criminal justice statistics

Criminal justice statistics are important statistics which help the public understand the nature of incarceration in their country.

There are examples within official statistics relating to criminal justice across England and Wales and Scotland where breakdowns of the data are presented by sex, with data marked as ‘female’ and ‘male’. The data used to produce the statistics comes from the court system in each country. It is recorded by an operational officer and this means there can be variation in the way data about sex is captured across the system. This means it is not possible to know what definition of sex is being captured. This can, in turn, place limitations on how some criminal justice statistics can be interpreted and used.

In this instance, it is hard for the statisticians to change the administrative systems, but they can understand them. OSR would expect producers of the statistics to:

  • understand the nature of the data they are currently using to produce their statistics
  • clearly state how data about sex are gathered
  • clearly explain any terminology in the statistics – the Ministry of Justice does this well in its Statistics on Women and the Criminal Justice System publication, and in the associated technical guide
  • have robust quality assurance measures in place
  • clearly explain any limitations of the data and the impact these have on the statistics and their use. In addition, we would encourage producers to build relationships with their data suppliers, so that they can have the conversations to seek change where there is an identified need, and it is feasible

Finalising the guidance

We published this guidance on collecting and reporting data about sex in official statistics as draft and welcomed comments from statistical producers and other stakeholders. Thank you to those who shared your views with us.

In the coming months we will be reviewing all the feedback we received before finalising the guidance.

If you have any questions, queries or further feedback as we go through this process we would be happy to hear from you. Please email us.

Unlocking the value of data through onward sharing

About this guide

We have written this guidance to increase awareness among statistics producers and users that the principles of the Code of Practice extend beyond statistics production to data sharing and access. We outline practices and processes that uphold these principles. Specific guidance about how to meet these expectations is signposted where available.

The central purpose for all official statistics producers is serving the public good through the provision of data and statistics. This obligation is reflected in the principles of the Code of Practice for Statistics which requires statistics producers to commit to, and to promote, the safe onward access to the data used as the basis for producing official statistics. These may include, for example, data from the census, population and business surveys, as well as administrative records.

This guidance is a companion to our guidance on data governance: building confidence in the handling and use of data, which supports data sharing for the public good. It is aimed at Heads of Profession for Statistics and analysts working in producer bodies with an interest in data linkage and sharing.

“Data is more useful when more people can access and use it. It is most useful when it can be joined together. Data that is inaccessible – or where access takes so long it is rendered irrelevant – is of limited utility. Jeni Tennison, CEO of the Open Data Institute[1]

[1] https://osr.statisticsauthority.gov.uk/odi-data-blog/

Guidance for producers when making changes to statistical methods

About this guide

This guide sets out examples of the principles in the Code of Practice that producers need to adhere to in order to remain code compliant when making changes to statistical methods. It also includes examples of the kinds of materials that can be used to help document this adherence. An important decision will be on the scale and nature of the changes that are being considered and to be proportionate in applying these principles – you need to determine the materiality of the change. Identify if there are fundamental changes to the methods that could affect the statistics – these will need to be understood and explained to users.


Thinking about quality when producing statistics

Statistics should be produced to a level of quality that meets users’ needs, and quality assurance (QA) should be proportionate to the nature of the quality issues and the importance of the statistics in serving the public good.

In this guide we provide some questions that analysts producing statistics can use in considering quality at each stage of production. This list is adapted from a series of questions we asked teams during our review of the principles and processes underpinning the quality of HMRC’s official statistics, and draws on QAAD Questions which help producers find out about administrative data.

This quality guide is not a checklist but is designed to be used alongside your own organisation’s guidance, as well as alongside external resources – take a look at the list at the end. GSS guidance on best statistical practice for quality assurance is available on the Policy and Guidance Hub.

OSR Review of approaches to addressing weaknesses in the RPI

In OSR’s Regulatory Work Programme for 2019 to 2020 in respect to the economy theme,  among our priorities for the year is regulatory work on inflation statistics. We cited work arising from any change to the Authority’s approach to the RPI and to the measurement of Owner Occupiers’ Housing Costs within ONS’s CPIH statistics.  Following a request from the RPI/CPI user group that OSR consider the proposed changes to the RPI with respect to the Code of Practice for Statistics, the Chair of the UK Statistics Authority, Sir David Norgrove, wrote to the user group. OSR’s response to the concerns of the user group can be found here in the annex to Sir David Norgrove’s letter. OSR expects to publish the findings from its review of ONS’s recent work on CPIH statistics in March 2020.

Experimental statistics – official statistics in development

About this guidance

This guide sets out the Office for Statistics Regulation’s expectations regarding the production and handling of experimental statistics, a subset of official statistics going through development and evaluation, in line with the Code of Practice for Statistics.

The Code of Practice encourages innovation and improvement and highlights the need for National Statistics and other official statistics to remain relevant for use, to provide a dynamic public service.

Regulatory guidance – Publishing official statistics and National Statistics

Updated December 2018: This document has been updated to clarify the section ‘Sharing official statistics and other statistics prior to release’.

Answers to questions we have received about publishing official statistics in line with the Code of Practice for Statistics.

If you have any questions you would like answered, please email the regulation team.

Topics covered:

  • Pre-announcing the release of statistics
  • Labeling the status of the statistics
  • Sharing official statistics and other statistics prior to release
  • Publishing ad-hoc statistics releases
  • Revisions and corrections

Regulatory guidance – Building confidence in the handling and use of data

This guide provides some further insight for statistics producers into the principle T6 Data Governance when handling data to produce and publish official statistics, and when making that data available to external users, in ways that are transparent and accountable (see page 3). It also draws on our findings from a review of the UK statistics system’s ability to provide greater insight to users via linked data: joining up data for better statistics. We have summarised lessons from this review (on pages 4 and 5), to give examples of the actions that producers can take to maximise the potential of data when producing official statistics. They illustrate practices that we look for when assessing compliance with the Code of Practice for Statistics.

UPDATED 22 October 2018: the list of relevant legislation has been extended to include the Statistics of Trade and Employment (Northern Ireland) Order 1988 (page 3).