Update on the harmonisation of disability data collection in UK surveys (part 1).

Abstract

Background: This article reports progress to date in the development of new National Statistics harmonised questions: measuring disability in established national social survey sources using a face-to-face interviewing mode of data capture. The harmonisation of these questions across these survey sources will enhance the availability of consistent disability statistics to government and the wider user community.This work began in response to the recommendation of the Review of Equality Data published in 2007: to develop and apply a principled approach to data collection to meet future data needs, following the introduction of equality legislation in 2010. It also contributes to improving international comparability, by better meeting the definitions for measures of long-standing illness and disability derived from the European Union's Statistics on Income and Living Conditions (EU-SILC).Further work is currently being undertaken to adapt questions for use in surveys applying different methods of data capture, such as paper-based and on-line surveys.The project also developed questions which measure disability as a restriction in participation in key areas of life such as employment, and the self-perceived social barriers affecting participation (that is aspects of society and the physical environment, which do not take adequate account of the needs of people with impairments). However, at the time of writing, a finalised standard had not been agreed: these data inputs will be reported on in a future Health Statistics Quarterly article.

Methods: The National Statistics Harmonisation Group (NSHG) and its Health, Disability and Carers Sub-Group contain representation across government, related public sector bodies and academia. These groups agreed the following project objectives for disability data harmonisation:a) Establish a conceptual framework for disability definitionb) Develop question inputs to measure the definition for use in social surveys using a face-to-face interviewing method of data capturec) Test the performance of these questions for interpretability and consistency with established sources, and refine questions, where indicated, through the findings of testing and consultationd) Recommend harmonised standards for implementation across sourcesA process of question suite development included: user consultation, which gathered cross-sector views to clarify and prioritise data needs; cognitive testing, which guided question formats, content and terminology, and interviewer probes and instructions. The findings of these exercises were used in the construction of questions which were subsequently field tested for coherence with other data sources and described in an accompanying article in this issue of Health Statistics Quarterly.

Results: The definition of disability developed to harmonise standard data inputs and outputs is founded on the Disablement Process (Verbrugge and Jette 1994), and the bio-psycho-social model of disability used in the International Classification of Functioning, Disability and Health (ICFDH) (WHO, 2001). This model presents disability as a process bringing together medical, societal and individual factors which affect daily activities and participation and disentangles concepts of illness, impairment and disability. Disability is defined as restriction in activities and participation related to the interaction between functional impairment and the provision of supports (personal, mechanical and environmental/societal).The results of cognitive testing found issues with the proposed question formats, interpretation of key terms such as 'disability' and sensitivities to the negative focus of questions; the researchers made a number of recommendations to improve the flow of questions and improve interpretation, including better signposting and use of interviewer probes and instructions, and changes to the terminology used in the body of questions and their response categories.

Conclusions: The extensive consultations undertaken, including government departments, other public sector bodies, academia and third sector organisations, demonstrates a clear commitment on the part of the Health, Disability and Carers Harmonisation Sub-Group to gather a wide range of views to identify the deficiencies in existing data inputs to social survey data sources; guide priorities as equitably as possible to meet the variety of needs expressed; and to lessen the sensitivities associated with existing question terminology when drafting question inputs.The application of respected conceptual frameworks and internationally recognised definitions and classifications to the data needs identified, and the modifications suggested following cognitive testing has given the draft questions for field testing a stronger relevance to the concept of disability advocated in the Prime Minister's Strategy Unit Report 'Improving the Life Chances of Disabled People' and championed in the Office for Disability Issues Equality 2025 agenda.