Review of disability data harmonised standards: findings from phase 2 of our research

Our initial research, published in the first review of the standards found that there is subjectivity in how people interpret the response options “a little” and “a lot” when asked about the extent to which a health condition limits their daily activities. This leads respondents to feeling unsure as to how they should be answering the question.    This inconsistency poses a challenge for data comparability and reliability.

To understand this issue better, we conducted two separate pieces of qualitative research with charity groups and ONS interviewers. As a result of this work, we found additional evidence that respondents do not consistently interpret the difference between the two response options “a little” and “a lot,”.  The research revealed that inconsistent interpretations between respondents often arise because respondents may make changes to their lives, or adapt, because of their condition. As a result, they may not feel as restricted in their day-to-day activities.

“It’s a difficult one because people, people … change their lives… to adapt to the limitations that there are in society because of their conditions or illnesses.”

Quote gathered from our research with ONS interviewers

“You know, if people have restricted their lives because of their condition and they’ve sort of lowered their expectations of what they might be able to do. They might answer this not at all. Whereas an outside observer might consider that they’ve limited their activities…”

Quote gathered from our research with charities

Our initial report explored the relationship between impairments and their relationship with medical conditions.  The research found that respondents often struggle to distinguish between their medical condition and its resulting impairment, which makes it difficult to respond to the impairment standard question.  The research highlighted two key issues; that we cannot be sure that respondents are answering the impairment question consistently, nor that data users are correctly interpreting the data.

In our latest research we have explored these issues further, and analysis of write-in responses to the impairment question in the Opinions and Lifestyle survey has strengthened our evidence that this is an issue. Instead of answering how they are impaired, we have found that respondents will often list their medical conditions in response to the impairment question. The most common examples of this happening within the Opinions and Lifestyle survey were in relation to conditions such as arthritis, diabetes, blood pressure, cancer, and osteoporosis. These are typically not considered impairments, but instead are medical diagnoses, and thus not intended to be captured in this way within this question. Previous research also highlighted that impairments may relate to multiple health conditions, and that a primary impairment may then lead to impairments in other areas.

There is also overlap between the impairment response options. This makes it difficult for respondents to determine which option or options they should select and which of their impairments they should be reporting. This may then influence the consistency and accuracy of reporting, and responses may not accurately reflect the experience of respondents.

Our additional research has given further weight to this issue.

“If you look at ‘Mobility’ and ‘Stamina or breathing’, those can both be tied together. Is it mobility independently or is it mobility because I literally run out of gas because I can’t breathe, there’s no oxygen coming to my body.”

-Quote gathered from our research with ONS interviewers

The relationship between impairments and medical conditions is nuanced. The current harmonised standards fall short in capturing this complexity, leading to underreporting or misclassification. Incorporating clearer language, and more inclusive examples in the standards in future will help ensure that disability data more accurately reflects the lived experiences of respondents.

Our initial research found that the response options for the current impairment standard are incomplete and limited (though the review does also acknowledge that the standard was created not to be comprehensive, but to reflect impairments most useful and relevant for categorisation to aid policy and service needs assessment). Cognitive testing found that the response options largely covered what participants expected but suggested that options for incontinence and communication should also be included.

We have since conducted additional quantitative and qualitative research to explore the need for additional response options more broadly.  In contrast to the findings from the initial review, our further research has found that respondents quite often struggle to see themselves within the response options, and that there is a heavy reliance on the use of the “other” write-in option.

“There are occasionally things that they [respondents] mention that they’re not sure what to categorize them as themselves; they do not seem to fit within the bands, so we end up putting ‘Other’”

Quote gathered from our research with ONS interviewers

Research was undertaken to analyse the use of the “other” write-in response option for the current impairment standard, across five waves of the Opinions and Lifestyle Survey. Responses were themed, and then grouped into three categories:

• responses that fit in directly with the current groupings (for example, where the same wording was used by the respondent as is used within other response options)
• responses that fit in with the current groupings but not directly (for example, where respondents identified a condition or conditions which you might expect to be associated with an impairment included in the existing response options)
• responses that do not fit in with the current response option groupings at all, and may therefore need a new option, or responses which reported a specific medical condition with unknown associated impairments.

Findings from this research showed that there was a much higher percentage of “other, please specify” write in responses that did not fit into the current standard at all (63.8%) compared to responses that fit directly (10.3%) or that fit indirectly (25.8%). The most frequently reported impairments which we determined do not fit into the current response option categories were pain, sleep, diet and weight issues, and incontinence.

Our first review also highlighted “communication” as a possible additional response option for the impairment question. This response option was considered when the question was developed in 2009, but ultimately it was not included. Our additional research has not found substantial evidence of a need for a “communication” response option at this time. Further work on the standards will be needed to determine which additional response options are required for these questions, and how these are understood and used by respondents.

Our analysis of responses to the Opinions and Lifestyle survey helped us to better understand the issue highlighted in our previous report on the guidance for impairment response options.

Our initial report highlights that respondents found this guidance was confusing and incomplete. Additional research has strengthened our understanding of this issue, highlighting particular areas of the guidance which are confusing, and has confirmed that the guidance will need to be updated. Response options and guidance that were identified as confusing were:

• “stamina or breathing or fatigue”
• “dexterity”
• “mobility”
• “vision”
• “mental health”

Our findings show that further testing of guidance for these response options will be needed, alongside exploring alternative response options through an iterative question design cycle.

“I’m not sure how well it fits for respondents to understand it [the guidance and impairment categories] well and instinctively, and obviously, the more time we have to spend on a question, the more we’re increasing that respondent burden on what we’re asking of them.”

Quote gathered from research with ONS interviewers

In our previous report, the Harmonisation team explored the possibility of three high-level groupings for use with the current standard. This was because stakeholders often found that the number of response options given for the impairment standard meant that often sample sizes were too small for analysis. The three high-level groupings for use with the current standard were:

• physical impairments — which includes “dexterity”, “mobility”, and “stamina”
• sensory impairments — which includes “hearing” and “vision”
• mental or cognitive impairments – which includes “memory, “mental health”, “learning or understanding or concentrating”, and “socially or behaviourally”

To create two high-level groups, the physical and sensory impairments can be combined.

In our latest phase of work, the issue of impairment option sample sizes was discussed in detail with multiple groups of stakeholders, from across government, academia, charities and Disabled People’s Organisations.

There was a strong emphasis in these conversations on ensuring that data collected using the harmonised standards must be usable for policy and service design. This requires adequate sample sizes to support robust analysis. Many users require data on disability to be analysed in relation to different subgroups, and therefore the impairment standard is only useful if there are large enough numbers in each category. Stakeholders expressed that the application of the current impairment standard is limited because of this. In general population surveys, the impairment question is less used because sample sizes for each impairment type are often too small to support reliable analysis.

In contrast, stakeholders also requested changes to the impairment standard, to increase the granularity of their data. This was viewed to be essential for accurately identifying subgroups, avoiding conflation of distinct conditions, and improving data utility.  Stakeholders highlighted that currently, the impairment categories are too broad and overlapping, and that this limits the analytical value of the data being produced. Without more granular data, it is difficult to understand how different impairments interact or co-occur. This limits the ability to assess barriers or outcomes for specific groups.

Further work on the standards will be needed to consider how to balance these conflicting needs. Work will need to be undertaken first to identify which additional response options are required, before we can then decide what the best approach for grouping these impairments and monitoring of their statistical performance is in the future.

Our initial report stated that it was unclear whether the current standards capture information about people with progressive and fluctuating conditions that may or may not affect their day-to-day activities. To understand this issue better, we explored this within our additional research with ONS interviewers, and in engagement activities with stakeholders. It is now clear, as a result of this additional research, that the current standards do not appropriately capture information around progressive and fluctuating conditions, and this is a concern for data users. The lack of clarity around how progressive and fluctuating conditions should be reported, also makes it difficult for respondents to answer these questions.

“Then there is the progressive illness such as ME [Myalgic encephalomyelitis]. There [was a] lady yesterday with ME, and none of those boxes cover anything of that nature; cancer, ME, Parkinson’s disease, etc.”

Quote gathered from research with ONS interviewers

There was also uncertainty in our initial report as to whether the current standards capture conditions which should be included as a disability from the day of diagnosis, as stated by the Equality Act 2010. This includes cancer, HIV infection and multiple sclerosis. If we wish to align with the Equality Act 2010 definition of disability, then it is important that these conditions are considered within the standards.

“People often say ‘cancer.’ They have had cancer, but they’re in remission, and its six to eight months ago, they’ve started the treatment and they’re in remission. Does that still count as long term?”

Quote gathered from research with ONS interviewers

Analysis of the Opinions and Lifestyle survey as part of our additional research, evidences that often, respondents will use the “other” write-in response option to report issues such as cancer. Indeed, cancer was one of the most common write-in responses within the impairments question on the Opinions and Lifestyle survey. Stakeholders also reported concerns that these groups were not being captured.

Whilst we can now be sure that this is an issue, further testing with respondents will be imperative in understanding the extent of this issue in practice.

We found evidence for this issue in our initial research.  However, the findings from our initial report suggested that this was primarily an issue with the activity restriction standard. Further research has highlighted that the interaction of treatment and medication with medical conditions causes confusion for respondents across all three disability and impairment standards.

Focus groups with charities stressed that the long-lasting health condition question is open to subjectivity as it does not specify whether you need to have a diagnosis to answer ‘yes.’ The Equality Act 2010 definition of disability includes people who have a condition regardless of whether they are receiving any treatment or medication.  Charities expressed a preference that respondents should be able to self-identify, and this also aligns with the social model of disability. However, feedback suggested that there needed to be more clarity, so that respondents better understood this.

In relation to the long-lasting health condition and illness standard, the same sentiment was reflected in focus groups with ONS interviewers, noting that respondents would be less likely to respond in the way the question intends had they not had a diagnosis, treatment, or medication.

“They don’t view that they have an illness or a condition because they are taking medication, and therefore it doesn’t affect them.” ​

Quote gathered from our research with ONS interviewers

“It depends how people self-identify. If they haven’t been properly diagnosed they may not see it as a condition or illness.”

Quote gathered from our research with charities

The same problem was also identified in relation to the impairment standard. Research with ONS interviewers suggested that even though the question relates to the impact of a person’s condition on their life, rather than the medical condition itself, participants may still experience confusion in answering the question. This may be because:

• Medication or treatment impacts on the level of impairment for some respondents
• There may be hesitation around reporting on an impairment if someone has not been diagnosed or is not being treated for a medical condition.

Our initial report outlined the three most applied models of disability; the medical model, the social model and the biopsychosocial model – and where each of the current disability and impairment standards align to these. The report highlighted that stakeholders most commonly requested alignment to the social or medical models. Our additional research and engagement work sought to explore this further, in order for us to set out an approach for the standards going forward.

As outlined earlier in this report, we have found additional evidence that a key requirement from stakeholders is that the standards align with the Equality Act 2010 in Great Britain and the Disability Discrimination Act 1995 in Northern Ireland. Both Acts define disability in ways that are broadly consistent with a medical model approach.

However, our discussions also highlighted a growing shift among organisations toward adopting the social model of disability. This includes a commitment from both Welsh Government, and Scottish Government to the social model of disability. This was also highlighted in our previous report, but more exploration was needed as to the weight of this need. The social model views people as disabled not by their impairments, but by the societal barriers they encounter. This shift has created a tension between two important objectives: the need to collect data on specific disabilities, health conditions, and illnesses to meet legal obligations, and the need to capture how these factors affect the lives of disabled people and the barriers they face.

In practice, many organisations want to continue collecting data that aligns with the legal definition of disability under the Equality Act, while also gathering additional information on impairments and the broader social and environmental barriers experienced by disabled people. As a result, stakeholders have made it clear that both the medical and social models must be considered when updating and refining the current standards.

We hope to be able to create a suite of standards for disability and impairment, which reflect the needs for data pertaining to both the medical and social models. This would allow users to choose which questions best align to their needs. Designing updated standards that meet a wide range of user needs while ensuring consistency across data sources is a complex task.  Consideration will also need to be taken regarding the comparability of data collected via the updated standards, with that of the current ones. An iterative process of prototyping and testing will be needed to ensure that changes to current questions and additional questions align to data user and respondent needs. We will continue to engage with stakeholders on this work to deliver a standard which is fit for purpose across a wide range of organisational contexts.

This was an area that was highlighted as including conflicting views in our first report, as the term “disabled” is contentious. In this report, we reflected on the decisions made to test the standards before it was last updated and highlighted that users at that time expressed a need to avoid combining the concepts of impairment and disability. However, more research was required to fully understand how respondents and users define and identify with different terminology. We have therefore undertaken significant research to understand the acceptability of different terms relating to the topic of disability, including a survey with the public that explored respondent perceptions of the terms used in the current standards.

There are a wide range of views on the usage of this term across our user groups. This was highlighted in particular by respondents, charities and Disabled People’s Organisations.  For some, there is a preference for the use of the term disabled, or disability, over the current wording of “long term health condition or illness”. This is because:

• some users and respondents believe the term to be factual and accurate
• the term is widely used and well understood
• the term communicates a need to others
• it aligns to legal processes, definitions and requirements

“I am disabled; there is truly no other word for the day to day experience I have with my body and the limitations to daily living activities created by my health conditions. “

Quote gathered from survey research with the public

“It’s just a term to help others understand that you may need a little bit extra in the way of understanding or help.”

Quote gathered from survey research with the public

“The term disability is as much a legal protection as it is a commentary on ‘lack of’ ability”

Quote gathered from survey research with the public

However, we know that many people do not identify with either “disability” or “long term health condition or illness”. Our terminology survey, which aimed to understand the acceptability of terms relating to disability and impairment highlights the need to explore other language. 31.7% of respondents who responded to our terminology survey, said they felt uncomfortable or very uncomfortable with the term ‘disability’. This is compared to 8.5% who felt uncomfortable or very uncomfortable with the term “physical or mental health condition or illness”. The reasons that participants gave as to why they did not accept the term “disabled” included:

• the negative connotations associated with the term
• some individuals do not identify as disabled
• the term may seem too extreme for individuals to use to describe their own health conditions
• the term is too broad
• the term may be misunderstood by other people
• the term reinforces the medical model
• use of the term may result in discrimination

“The word itself, for me, it conjures the idea that I am now a 2nd class citizen, I am not able to do some of the things that other can do”

Quote gathered from survey research with the public

“It feels like a term that isn’t ‘for’ me, and if I claim it, [it] feels like I’m taking away from people who are disabled, or more disabled.”

Quote gathered from survey research with the public

“It can imply that people with health conditions are not able to live properly, instead of stating that it is the society which does not enable people to live a normal life”

Quote gathered from survey research with the public

More work is required to test different terminology to ensure that the standards are inclusive, so that individuals can recognise themselves in the data and our standards, and so that the data collected via the harmonised standards is representative of the disabled population.

This is a new issue that has emerged as particularly important in our latest research. This is an issue that runs across the three standards on disability and impairment. There is also a strong link between this issue and several of the other issues discussed previously within this report.

Roundtables and focus groups with stakeholders emphasised that the terminology used in data collection has a direct impact on whether individuals feel represented, understood, and willing to respond. The language used in the current standards is not considered inclusive by stakeholders and respondents.

Key concerns raised include:

• The use of medicalised and outdated terms that do not reflect how people identify or experience disability.
• A preference for identity-first language (e.g. “autistic person” rather than “person with autism”) in many communities.
• Requests for clearer, plain English wording that resonates with lived experience and avoids jargon or clinical framing.
• The importance of language that reflects the social model of disability, focusing on barriers rather than deficits or impairments.

“I’m autistic and I wouldn’t describe that as an illness or a health condition. I would say that I don’t feel that relates to that either.”

Quote from our research with disability charities

” I favour the social model of disability. I don’t think the problem is me.”

Quote gathered from our survey research with the public

As outlined in the issue above, cognitive testing with respondents will be necessary to further understand how the language that is used in the current standards, and any possible alternatives, are perceived and accepted by the public. It is important to ensure that the language used across the standards is inclusive, that individuals can recognise themselves in these questions, and that the data collected via the standards is representative of the disabled population.

A recurring user need is for disability data that can be broken down in greater detail across a range of dimensions.

Throughout our research, users from across government, academia, the voluntary sector, and the public consistently called for questions that enable more granular analysis of disability, both in terms of the types of impairments and the characteristics of the individuals affected.

Specifically, users requested:

• The ability to distinguish between different types of impairments
• The ability to understand the severity of the health condition or illness, and impairment
• Data that allows for disaggregation by demographic variables such as age, sex, ethnicity, geography, and socio-economic status.

Questions that allow for more detailed breakdowns of disability data would allow users and decision-makers to understand how disability affects people with different characteristics, so that they can then design inclusive policies, and target services and interventions more effectively. Some organisations also highlighted that more granular data is needed for them to better meet the Public Sector Equality Duty, and to support equality impact assessments.

Our previous research, published in our first report on the disability harmonised standard, stated that one of the benefits of the current standards is that they allow for the expression of multiple impairments, conditions or illnesses. It is true that the standards do allow for respondents to select more than one response option for the impairments question, and that the long-lasting health conditions and illnesses standard is worded in a way that considers that respondents may have more than one condition or illness. However, many users expressed the need for data collection and analysis methods that more accurately reflect the lived experiences of individuals with multiple impairments or complex conditions.

Whilst the need for standards which support multi-impairment reporting was discussed in our previous review, further research and conversations with a variety of groups of stakeholders has highlighted how important this need is for many. We have also gathered more insight into why this is important for different types of stakeholders, and the implications for them, if they are not able to use data in this way. This is why we are now including it in this report as a distinct need.

Users called for standards that allow for the selection of multiple impairments and support nuanced analysis of co-occurring conditions. This need is important because people with multiple impairments often face unique challenges that are not visible when data is grouped too broadly. Users want to be able to select more than one impairment type and to see how combinations of conditions affect outcomes relating to areas such as employment, education, and health. Data users need to be able to understand how different disabilities and impairments overlap, or interact with each other, and the different outcomes for people with multiple conditions. Respondents want to be able to express their experiences accurately.

Harmonised standards that allow individuals to report multiple impairments and reflect the complex ways different conditions interact would allow government, local authorities and charities to identify gaps in support, and ensure that policies are inclusive of all disabled people—not just those with a single, clearly defined condition. It would also allow for better monitoring of inequalities and more accurate benchmarking across regions and services.

Until our updated standards are published, we encourage users to continue to use the current harmonised standards.

One of the most common data needs is to collect data according to its legal definition. There are two relevant harmonised standards that need to be used together to collect data on disability in line with the Equality Act (2010) for Great Britain, or the Disability Discrimination Act (1995) for Northern Ireland:

• the long lasting health conditions and illness harmonised standard
• the activity restriction harmonised standard

These standards have been designed specifically to capture the core disabled population according to UK legislation. Users can also collect data using the impairment harmonised standard to understand the activities that a person can and cannot do because of a health condition. There is also harmonisation guidance for mental health data, which explains the context of statistics without providing a preferred standard. We have published a review of the mental health standard alongside this guidance.

The current disability standards were published in 2011, and the question design dates back to 2008, as mentioned in Health Statistics Quarterly. Disability is an evolving topic, and it is important that the harmonised standards reflect the social and cultural environment in which they are used. Therefore, it is important that the standards are updated to reflect new thinking in the space. This has an impact on the data requirements for disability standards, which have changed because of:

• key stakeholders moving to view disability in line with the social model of disability
• Increasing data gaps as a result of complementary surveys changing over time, or no longer running

It was also recommended by the Inclusive Data Taskforce (IDTF) that standards should be reviewed every five years.

As the modes used to collect data are changing, there is a need to review how we optimise the standard for the mode and update it as needed. When designing for multiple modes, we always design the online mode first and then move on to develop the other modes. We do this because if a design can be easily used and understood in a self-complete mode, then it stands a high chance of being easily used and understood in an interviewer-led mode.  Further work is required to test iterations to the existing standards, across all modes. This would include working closely with data collectors and processors to develop an offering for harmonised administrative data.

The aims of the discovery phase of this work were:

• To understand the problem space relating to the disability and impairment harmonised standards
• to learn about our users and what they are trying to achieve when using the harmonised standards
• to understand ways in which the current standards could be improved, to better meet user needs

To complete this review, we have continued work outlined in the first findings report, particularly in relation to the areas of conflicting views that were highlighted. We have also conducted several new research activities, to ensure that the aims of discovery were met.

Continued Desk Research

Our research activities included:

• an implementation review of large-scale surveys which ask questions relating to disability and impairment. This included surveys from across government, research institutions, and charity groups.
• reviewing existing literature on the topic of disability and impairment, particularly in relation to different definitions of disability, and how these have been adopted in recent years.

Continued engagement with people who use or collect disability and impairment data via surveys and administrative data

Our research activities included:

• gathering feedback from administrative data collectors about the collection and use of disability data
• gathering feedback from government departments (including local authorities) and the devolved governments
• gathering feedback from academics, researchers, charities and Disabled People’s Organisations.

Continued engagement with the public

Our research activities included:

• analysing queries and feedback received by ONS regarding the use of the standards in the 2021 Census, and Future Population and Migration Project 2023 consultation. This included comments from members of the public and organisations.

New research

Our research activities included:

Opinion and Lifestyle (OPN) Survey Analysis

The Opinion and lifestyle survey (OPN) uses the disability harmonised questions. Analysis of five waves of the OPN, spanning from 2019 -2023, was undertaken to explore how the ‘other’ write-in response option was used by respondents when answering the impairment question.  This research helped us to understand:

• whether respondents are categorising their impairments in the way in which the question intended
• how well the current response options are working
• what the most common write in responses are for this question, and why they do not fit in with the current categories
• whether new response option categories may be needed for the impairments question going forward.

Focus groups with disability charities

To further explore the need for new response options in the impairment standard, and the strengths and weaknesses of the long-lasting health condition and illness and activity restriction standards, focus groups with disability charities were conducted in 2023. Four focus groups were conducted with a total of 16 respondents from a range of charities and Disabled People’s Organisations.

Exploring ONS interviewers’ experiences of asking the current disability and impairment harmonised questions

In 2022, the Harmonisation team conducted a survey of ONS interviewers. This survey was designed to capture how interviewers experienced asking respondents questions on ethnicity, disability, and mental health. This survey was conducted as part of phase one of discovery of the disability and impairment standards. As part of our research for discovery phase two, we conducted further research with ONS interviewers. In this phase, we conducted three focus groups with ONS interviewers to get more in-depth insight into the difficulties and issues that were identified within the original survey. Survey Interviewers provide unique insight into the ways in which respondents engage with questions during research at scale. By understanding their experiences of asking these questions across different surveys and contexts, we are better able to determine areas where respondents experience difficulties in answering these questions, and where interviewers are most often asked to clarify or explain the questions. This can have implications for the questions across modes.

Survey exploring public perceptions of the language used to describe disability and impairment

This survey (conducted in 2025) was designed to explore the public’s understanding and acceptability of terminology relating to the area of disability, particularly in relation to the language used in the current disability and impairment standards. The findings will help us to understand which terms are best understood by the public and will inform plans for future testing. The survey was completed by 568 respondents, who self-identified as having a disability, or long-term health condition.

Stakeholder webinar and roundtable events

In March 2025, the Harmonisation Team hosted a webinar for stakeholders across different sectors, with an interest in disability. This was followed by three roundtable events, with government, academic, and charity and Disabled People’s Organisations stakeholders to better understand their needs and requirements for the standards.

We would like to express our sincere thanks to everyone who has contributed to this review, whether by participating in our research or by sharing their insights, needs, and concerns about the current standards.  Your insights and feedback have been crucial in guiding our work to ensure the standards are relevant, inclusive, and effective. We are grateful for your continued support.