Sickness, both long-term and temporary, was the main reason given for not working by people aged 16-64 years living in workless households across the UK, the Office of National Statistics (ONS) has found.
In Northern Ireland, of the people living in workless households, 36.4% said they were not working because of sickness or disability.
In Scotland, 33.7% gave this reason with 28.5% in Wales and 26.6% in England.
Across the regions of England the lowest percentage not working because of sickness or disability was in London where 22.2% of people in workless households gave this reason.
The research defined workless households as households where no-one aged 16 or over is in employment.
These members may be unemployed or inactive. Inactive members may be unavailable to work because of family commitments, retirement or study, or unable to work through sickness/disability.
Nottingham was the top workless area for the first time since comparable records began with 30.1% of households being workless. Glasgow City (29.8%) and Liverpool (27.2%) were in the top five workless areas for the tenth consecutive year.
The highest percentage of workless households in Wales was in the Central Valleys where 23.8% of households were workless, while in Northern Ireland, 20.3% of households were workless, the ONS said.
The lowest percentage of workless households in the UK was concentrated in South East England, with the lowest in West Sussex at 9.0%.
Excluding student households, Glasgow City was the highest workless area with 28.6% of workless households, followed by East Ayrshire and North Ayrshire Mainland (28.5%) and then Nottingham at 27.3%.
Commenting on the figures Peter Le Beau, chair of the Income Protection Task Force and one of the architects of the Seven Famiies initiative said: "The ONS Report underlines the prevalence of worklessness in the UK. Often the reason is linked to illness or accident and we hope the Seven Families will underline the financial vulnerability that worklessness brings and the need to factor the risk of falling ill into people's' financial planning."
