In November 2019 the BBC Shared Data Unit reported one in two people who appealed in court against a decision to deny them disability benefits was successful.

In total, more than 550,000 people won an appeal over their benefits at tribunal between 2013 and 2018.

The success rates showed benefits assessments were beset by "poor decision-making" and "obvious inaccuracies", charities said.

The government said only around 5% of all disability benefits claims were overturned.

Our research was raised at First Minister's Questions to Nicola Sturgeon in Scotland on the day of publication and it was put to the Secretary of State at the Department for Work and Pensions (DWP) Thérèse Coffey on the campaign trail on the same day. Coffey said the DWP was trying to address the issues identified in tribunals it had lost and reduce the numbers of its defeats "significantly". Labour's Shadow Minister for Disabled People, Marsha de Cordova and Eleanor Smith, standing in Wolverhampton South West, tweeted that the party would scrap the health assessments criticised by stakeholders in our report, if it won the General Election.

Benefits assessments are carried out on behalf of the DWP by the private contractors Capita, the Independent Assessment Services (formerly called Atos) and Maximus.

Capita and Maximus, two of the private companies who carry out assessments, said the majority of people were satisfied with the process and they worked with charities and disabled people's organisations to improve their services further.

The BBC's Shared Data Unit analysed figures from Freedom of Information responses from HM Courts and Tribunals Service and Northern Ireland's Department for Communities (DfC).

Most of the appeals concerned Employment Support Allowance (ESA), which is paid to people unable to work because of illness or disability; the Disability Living Allowance (DLA), which is paid to people with extra care or mobility needs; and Personal Independence Payment (PIP), which was introduced to replace DLA

The analysis found:

• About 553,000 successful appeals were heard at tribunal about disability, sickness and incapacity benefits out of 981,000 from 2013 to 2018
• Last year, around two thirds of cases heard in Great Britain found in favour of the claimant. In Northern Ireland, the figure was around 54% in 2018-19

The Shared Data Unit makes data journalism available to news organisations across the media industry, as part of a partnership between the BBC and the News Media Association. Stories generated by the partnership included:

• The Oldham Chronicle: More people from the North West winning benefits disputes over illness and disability 8 November 2019
• Plymouth Live: Benefit appeals investigation exposes plight of Plymouth claimants forced to fight for money 14 November 2019
• ITV North West: Granada News: Benefit system has been 'broken from the beginning' say North West team 14 November 2019
• The Scotsman: Scots with disabilities losing benefits due to ‘poor assessments’ 14 November 2019
• The Yorkshire Post: The Yorkshire ESA, PIP and DLA claimants wrongly denied benefits - new stats show the rising success of appeals 14 November 2019
• Blackpool Gazette: The poorly and disabled are taking on the government in their fight for benefits - and most of them here in the north west win 14 November 2019
• Devon Live: Benefit appeals investigation exposes plight of Plymouth claimants forced to fight for money 14 November 2019
• Fleetwood Weekly News: The poorly and disabled are taking on the government in their fight for benefits - and most of them here in the north west win 14 November 2019
• Rochdale Online: More disabled people are winning benefit appeals at tribunal 14 November 2019
• Cornish Stuff: More than half now win benefits appeals 14 November 2019
• Cornwall Live: Benefit appeals investigation exposes plight of Plymouth claimants forced to fight for money 14 November 2019
• Galloway Gazette: Thousands win appeals after being wrongly denied disability benefits 14 November 2019
• The Brecon & Radnor Express: General election: Work and Pensions secretary visits constituency 14 November 2019
• North East: Chronicle Live: More than half of people who appealed being denied benefits by DWP won their case 14 November 2019
• Glasgow South and Eastwood Extra: Thousands win appeals after being wrongly denied disability benefits 14 November 2019
• The Carrick Gazette: Thousands win appeals after being wrongly denied disability benefits 14 November 2019
• Berwickshire News: Thousands win appeals after being wrongly denied disability benefits 14 November 2019
• Third Force News: Revealed: Over half of Scots win disability assessment appeals 14 November 2019
• Access and Mobility Professional: Welsh disability benefit denial court appeals against UK government win four in five times 14 November 2019
• Wigan Today: Wiganers could be on to a winner in benefits cases 14 November 2019
• Wigan Today: Wigan residents wrongly denied hundreds of thousands of pounds in benefits as Citizens' Advice speaks of toll system takes on claimants 15 November 2019
• Thiis (The Homecare Industry Information Service) Magazine: PIP assessments under fire again as new data shows half of disability benefits appeals won in tribunal court 15 November 2019
• Teesside Live: DWP: Disabled Teessiders wrongly denied benefits are increasingly beating the government at appeal 17 November 2019
• Evesham Journal: 70 percent of Midlands disability benefit appeals successful 17 November 2019
• Worcester News: 70 percent of Midlands disability benefit appeals successful 18 November 2019
• Droitwich Spa: 70 percent of Midlands disability benefit appeals successful 18 November 2019
• Hereford Times: 70 percent of Midlands disability benefit appeals successful 18 November 2019
• Belfast News Letter: More than half of disability benefits appeals in NI won in tribunal court 16 December 2019
• Ballymena & Antrim Times: More than half of disability benefits appeals in NI won in tribunal court 17 December 2019
• Mid Ulster Mail: More than half of disability benefits appeals in NI won in tribunal court 19 December 2019
• Portadown Times: More than half of disability benefits appeals in NI won in tribunal court 20 December 2019
• Banbridge Leader: More than half of disability benefits appeals in NI won in tribunal court 24 December 2019
• Coleraine Times: More than half of disability benefits appeals in NI won in tribunal court 25 December 2019
• Londonderry Sentinel: More than half of disability benefits appeals in NI won in tribunal court 25 December 2019
• Lurgan Mail: More than half of disability benefits appeals in NI won in tribunal court 26 December 2019
• Derry Journal: More than half of disability benefits appeals in NI won in tribunal court 31 December 2019

The story was also used by the BBC national TV news at 1pm, Today - BBC Radio 4, Afternoon Live - BBC News Channel, BBC Reporting Scotland, Wales Today, BBC South Today, BBC Look North (Newcastle), BBC Wales online, BBC Tees, BBC Radio Ulster, BBC Somerset, BBC Radio Kent, BBC Radio Solent, BBC Radio Suffolk, BBC Radio nan Gàidheal - Naidheachdan, BBC Radio Foyle and Radio Scotland

• UK-wide figures

• Line chart: Percentage of tribunal decisions in appellants' favour from 2013-18 for Great Britain and Northern Ireland
• Line chart: Drop in all benefits appeals to First-tier tribunal in the year after Mandatory Reconsideration and legal aid cuts took effect

• A full briefing pack on the story can be found here