Understanding the drivers of changes in demand for disability benefits in Scotland since 2010: A quick scoping review

4. Methodology

As explained in the introduction, quick scoping reviews systematically map the research carried out in an area and provide a general understanding of the volume and characteristics of the evidence base, as well as identifying any existing gaps in knowledge.^[34] They allow questions to be answered by maximising use of existing evidence, whilst also providing a clear picture of the adequacy of that evidence using methods that are designed to be transparent and to minimise bias. This approach was considered the most appropriate review type to address the research questions.

4.1 Protocol

This review adheres to the guidelines set out in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR),^[35] and drew on resources developed by the JBI.^[36] The protocol is in Annex 1.

4.2 Inclusion criteria

The timeframe of interest was from 2010 - (June) 2025 and sources were only included if published after 2010. This report focusses on evidence relating to disability benefits in Scotland but also includes evidence at a wider UK level and places developments in Scotland within the broader UK and European context. Sources were only included that incorporated evidence from Scotland, the rest of the UK, and/or Europe. Only sources published in English were eligible for inclusion.

The population of interest was disabled people (children and working-age adults) or people receiving disability or incapacity benefits. People of state pension age were not included. However, it is worth noting that working-age disability benefits include people of pensionable age and so analyses of PIP and ADP data will include some people of pensionable age.^[5] The topics of interest were disability/incapacity benefit caseloads (for secondary questions) and drivers of disability/incapacity benefit caseloads up (for primary questions).

4.3 Information sources

The library search identified 264 potentially relevant sources, through searches of Idox, KandE, Knowledge Network, Policy Commons, ProQuest, Google Advanced Search, Google Scholar, and Google Custom Search. This search was supplemented with other sources and grey literature^[6] which added a further 98 sources.

4.4 Search strategy

The search strategy was developed following analysis of text words contained in titles and abstracts of relevant reports/articles, as well as discussion with the Research Advisory Group. The full list of search items / keywords can be found in the protocol in Annex 1. The search strategy, including all identified keywords was adapted for each database.

Literature searches were conducted by the Scottish Government Library Services between 22 May and 4 June 2025. This included all types of peer-reviewed and non-peer reviewed publications but did not include unpublished sources. The 98 ‘other sources’ and grey literature were identified through independent web searches (including Google Scholar, think tank webpages etc.), following up cited references in papers and consultation with academic experts.

4.5 Selection of sources of evidence

Following the search, all identified citations were collated and stored in Excel and duplicates removed. Throughout the process, 12 duplicate records were identified and removed. The library was unable to provide a full list of duplicates removed and so this number is likely to be an underestimate. Following a pilot screening phase in which the inclusion criteria and screening process were refined, titles and abstracts were screened by two independent reviewers. Sources were categorized as ‘clearly relevant,’ ‘clearly not relevant,’ or ‘uncertain.’ Papers were marked as ‘uncertain’ if it was unclear from the title and abstract alone whether the source was relevant or not, and these sources were retrieved in full, full text screened and categorised as ‘clearly relevant’ or ‘clearly not relevant.’ For any papers not marked as relevant after full-text screening, the reason for exclusion was recorded. All sources were checked by one reviewer, but ten percent of all sources (35) were checked by the second reviewer. Any disagreements that arose between the reviewers at this or any stage of the selection process were resolved through discussion or with input from additional reviewers. Once all sources had been screened, the reviewers looked at each included source together to ensure full agreement. Upon completion of the screening stage, 23 sources were included.

4.6 Data extraction

A JBI data extraction template^[37] in Microsoft Excel was used to extract data from the included studies and modified slightly to account for the five different outcomes (drivers) and the fact that both primary and secondary questions were being addressed. Data were recorded independently by two reviewers to minimise bias and reviewers piloted the extraction tool by initially extracting data from five studies. The final extraction form recorded the title of the publication, authors, year of publication and geographical context, and information about the population. The aim/purpose of the study was also extracted as well as the general methodology and what type of source it was (e.g., study, report). For ‘outcomes’, a record was kept of whether the source discussed each driver by selecting ‘yes’ or ‘no’ as well as whether it addressed the contextual questions (again with a ‘yes’ or ‘no’ response). The key findings for each source were noted, categorised by primary and secondary questions, and any other notes worth recording were added. A note was kept of where any secondary sources drew information from.

4.7 Results

4.8 Description of sources

Twenty three sources were identified which met the inclusion criteria. Fourteen of these examined the drivers of disability benefits independently, while nine of the 23 included incapacity benefits or discussed health-related benefits. Table 1 summarises the full-text sources included in the review. Note that for the ‘analysis’ column, “primary (statistical) analysis of published data” refers to the source that conducted new, statistical analyses on published data, “secondary analysis of published data” refers to sources that used published, raw administrative and/or survey data to report figures, generate tables/graphs and explain trends, and “review of existing research” refers to sources that investigated and/or discussed drivers by reviewing other existing research (involved no further analysis of data).

The predominant study designs used in these sources (21 out of 23) was secondary analyses. Only two of the sources were primary studies - in one, qualitative data was collected specifically for the purpose of the study, and in the other secondary data was used but primary statistical analysis was conducted. One further report included a stakeholder workshop. Four reports also included a review of existing research but involved no further analysis of data. Almost all the sources were grey literature (21 of the 23 sources), around two-thirds (16 out of 23 sources) were produced by think tanks and just over a third of sources (nine) were by the IFS alone.

4.9 Table 1: Summary of included sources

Details of the first source

• Author(s) - Banks, Karjalainen & Waters (Institute for Fiscal Studies - IFS)
• Published 2023
• Publication type - Report
• Location - UK
• Population includes Children, working-age adults
• Benefit types - Disability benefits, incapacity benefits
• Aim of publication - Summarise evidence on the prevalence of disabilities and inequalities in disability (and link some findings with health-related benefit take up)
• Drivers it relates to - Health, attitudes and behaviour, demographic changes
• Analysis type - Secondary analysis of published data

Details of the second source

• Author(s) - Basis Social
• Published 2025
• Publication type - Report
• Location – England and Wales
• Population includes Working-age adults
• Benefit types - Disability benefits
• Aim of publication - Examine different PIP claim ‘journeys’ amongst applicants and non-claimants
• Drivers it relates to - Attitudes and behaviours
• Analysis type – Primary (qualitative) study

Details of the third source

• Author(s) - Chaudhuri & Waters (IFS)
• Published 2024
• Publication type - Report - comment
• Location - Scotland
• Population includes Working-age adults
• Benefit types - Disability benefits
• Aim of publication - Examine how the number of disability benefit applications and awards has changed in Scotland
• Drivers it relates to - Health, benefit system
• Analysis type - Secondary analysis of published data

Details of the fourth source

• Author(s) - Congreve (Scottish Health Equity Research Unit)
• Published 2024
• Publication type – Report
• Location - Compares Scotland with England and Wales
• Population includes Working-age adults
• Benefit types - Disability benefits
• Aim of publication - Examine awards for disability benefits before and after the pandemic and compare Scotland to England and Wales
• Drivers it relates to - Health, benefit system, economy and labour market
• Analysis type - Secondary analysis of published data

Details of the fifth source

• Author(s) - Evans (Learning and Work Institute)
• Published 2025
• Publication type – Report
• Location - UK
• Population includes Working-age adults
• Benefit types - Incapacity benefits, disability benefits
• Aim of publication - Discuss drivers for the increase in the number of successful applications for incapacity benefits and problems with the current system
• Drivers it relates to - Health, economy and labour market, benefit system, attitudes and behaviour, demographic changes
• Analysis type - Secondary analysis of published data, Review of existing research

Details of the sixth source

• Author(s) - House of Lords Economic Affairs Committee
• Published 2025
• Publication type – Letter
• Location - UK
• Population includes - Working-age adults
• Benefit types - Incapacity benefits
• Aim of publication - A short enquiry to examine what is driving the increase in spending on disability and incapacity benefits
• Drivers it relates to - Health, benefit system
• Analysis type - Secondary analysis of published data, Review of existing research

Details of the seventh source

• Author(s) - Cribb, Karjalainen & Waters (IFS)
• Published 2022
• Publication type – Report
• Location - UK
• Population includes - Working-age adults
• Benefit types - Disability benefits
• Aim of publication - Examine the living standards and health of working-age disabled people and disability benefit recipients over time
• Drivers it relates to - Health, benefit System
• Analysis type - Secondary analysis of published data

Details of the eight source

• Author(s) - Joyce, Chaudhuri & Waters (IFS)
• Published 2022
• Publication type – Report  
• Location – England and Wales
• Population includes - Working-age adults
• Benefit types - Disability benefits
• Aim of publication - Investigate the sharp increase in PIP claims from 2021 to 2022
• Drivers it relates to - Health, economy and labour market, benefit system
• Analysis type – Secondary analysis of published data

Details of the ninth source

• Author(s) - Judge & Murphy (Resolution Foundation)
• Published 2024
• Publication type – Report
• Location - UK, England and Wales
• Population includes Working-age adults, children
• Benefit types - Disability benefits, incapacity benefits
• Aim of publication - Investigate trends in working-age health-related benefits and discusses each of the drivers often put forward to the explain these trends
• Drivers it relates to - Health, economy and labour market, benefit system, attitudes and behaviour, demographic changes
• Analysis type - Secondary analysis of published data, Stakeholder consultation

Details of the tenth source

• Author(s) - Latimer, Chaudhuri & Waters (IFS)
• Published 2025
• Publication type – Report
• Location - UK
• Population includes Working-age adults
• Benefit types - Disability benefits
• Aim of publication - Examine what different surveys tell us about working-age health and how this might be linked to the rise in disability benefit claims
• Drivers it relates to - Health, attitudes and behaviour
• Analysis type - Secondary analysis of published data

Details of the eleventh source

• Author(s) - Latimer, Pfanz & Waters (IFS)
• Published 2024
• Publication type – Report
• Location - UK
• Population includes Working-age adults
• Benefit types - Disability benefits, incapacity benefits
• Aim of publication - Examine how individuals who receive disability benefits now compare with those who began applications before the pandemic (and compare with other countries)
• Drivers it relates to - Health, economy and labour market, benefit system
• Analysis type - Secondary analysis of published data

Details of the twelfth source

• Author(s) - Mosley (New Economics Foundation)
• Published 2025
• Publication type - Blog
• Location – England and Wales
• Population includes Working-age adults
• Benefit types - Disability benefits
• Aim of publication - Examine what is behind the rise in disability benefit claims
• Drivers it relates to - Health, economy and labour market, benefit system
• Analysis type - Secondary analysis of published data

Details of the thirteenth source

• Author(s) - Murphy (Resolution foundation)
• Published 2024
• Publication type – Report
• Location - UK
• Population includes children
• Benefit types - Disability benefits
• Aim of publication - Examine trends in children’s disability benefits
• Drivers it relates to – Health
• Analysis type - Secondary analysis of published data

Details of the fourteenth source

• Author(s) - Murphy (Resolution Foundation)
• Published 2025
• Publication type - Slide pack
• Location - UK
• Population includes Working-age adults
• Benefit types - Disability benefits, incapacity benefits
• Aim of publication - Set out principles to guide policy makers through reforming incapacity and disability benefits
• Drivers it relates to - Health, demographic changes, benefit system
• Analysis type - Secondary analysis of published data

Details of the fifteenth source

• Author(s) - Office for Budget Responsibility
• Published 2019
• Publication type – Report
• Location - UK
• Population includes Children, working-age adults
• Benefit types - Disability benefits
• Aim of publication - Explain trends in spending on disability benefits - emphasis on recent years, and to assess the impact that the introduction of PIP has had on public spending
• Drivers it relates to - Health, benefit system, behaviours and attitudes, demographic changes
• Analysis type - Secondary analysis of published data

Details of the sixteenth source

• Author(s) - Office for Budget Responsibility
• Published 2024
• Publication type – Report
• Location – UK
• Population includes Working-age adults
• Benefit types - Incapacity benefits, (some content on disability benefits)
• Aim of publication - Explore potential drivers of the increase in working-age IB caseloads, with focus on how changes in the operation of the IB system may have contributed to trends in successful applications, particularly since 2010
• Drivers it relates to - Health, economy and labour market, benefit system, demographic changes
• Analysis type - Secondary analysis of published data, Review of existing research

Details of the seventeenth source

• Author(s) - Ray-Chauduri & Waters (IFS)
• Published 2024
• Publication type – Report
• Location - UK
• Population includes (Mostly) working-age adults
• Benefit types - Disability benefits, incapacity benefits
• Aim of publication - Present and summarise the latest data on health-related benefits in the UK and discuss potential causes for the rise in caseload. Examine data before and after the pandemic
• Drivers it relates to - Health, economy and labour market, benefit system
• Analysis type - Secondary analysis of published data, Review of existing research

Details of the eighteenth source

• Author(s) - Scottish Fiscal Commission
• Published 2023
• Publication type – Report
• Location – Scotland
• Population includes Children, working-age adults
• Benefit types - Disability benefits
• Aim of publication - Provide forecasts for spending
• Drivers it relates to - Benefit system, economy and labour market
• Analysis type - Secondary analysis of published data

Details of the nineteenth source

• Author(s) - Scottish Fiscal Commission
• Published 2025
• Publication type – Report
• Location – Scotland
• Population includes Children, working-age adults
• Benefit types - Disability benefits
• Aim of publication - Provide forecasts for spending
• Drivers it relates to - Benefit system, economy and labour market
• Analysis type - Secondary analysis of published data

Details of the twentieth source

• Author(s) - Scottish Parliament
• Published 2025
• Publication type - Blog
• Location – Scotland
• Population includes Working-age adults
• Benefit types - Disability benefits
• Aim of publication - Consider how the proposals for PIP reform could affect Scotland
• Drivers it relates to - Health
• Analysis type - Secondary analysis of published data