Working days lost through sickness absence are at their lowest level in 20 years, a CBI report suggests.
Long-term illness accounted for 57% of public sector absence
The business leaders' group said the figure fell last year by four million days to 164 million days.
But the CBI says too much absenteeism remains in many workplaces and that 13% of sick days are not genuine. The cost of lost days to the economy was £13bn.
TUC General Secretary Brendan Barber said the report "smashes the myth" the UK is a "nation of shirkers".
"In fact the reverse is true and many people still struggle into work when they are far too ill to do so," he added.
The study shows that the Yorkshire and Humber region topped the regional league table for absenteeism, with 8.9 days lost per worker in 2005.
That was nearly twice the amount seen in Northern Ireland, with just 4.7 days lost per worker.
'More to be done'
The study, carried out with the assistance of insurance firm Axa, showed absentee levels were a third higher in the public sector than in private outfits.
Public sector staff took an average of 8.5 days a year off last year, down from 8.9 days in 2002.
Regional days lost per worker
Yorkshire/Humberside - 8.9
Wales - 8.4
Southern England - 7.7
East Midlands - 7.2
South West - 7.2
Scotland - 7.1
South East - 6.5
West Midlands - 6.4
Northern England - 6.2
North-west England - 6
Eastern England- 5.8
London - 5.1
Northern Ireland - 4.7
However those in the private sector only took an average of six days a year off in 2005, compared with 6.7 days in 2002.
If the public sector could reduce its absentee levels to that of the private sector then £1bn of taxpayers' money would be saved, the report claims.
Deputy Director General John Cridland said: "The huge cost of absence to the economy shows why so many chief executives declare that their people are their most important asset.
"Hard work by companies to manage absence is clearly paying off, with overall absence coming down. But so much more can still be done."
He added: "Nobody wants staff to drag themselves into work when they are genuinely ill, but there is clearly concern that a culture of absenteeism still exists in some workplaces and this must change."
World Cup games
Employers said unauthorised absence include workers taking time off to extend holidays or have a long weekend.
Mr Cridland also said many firms were worried about staff staying away from work to watch England's World Cup football matches this summer.
However he said many employers have put arrangements in place to allow games to be watched in the workplace.
TUC General Secretary Brendan Barber said: "Public sector workers have less short-term but more long-term absence rates than the private sector.
"Public sector workers report long term sickness more for two reasons. First many companies don't allow long term sick leave - you get the sack.
"Second some public sector workers are more likely to be attacked or suffer stress because of their jobs."
He said only "lazy employers" believe the solution to excess sick leave is to emphasise the stick. And he said as England's World Cup matches were evening kick-offs there were unlikely to be many "sickies" taken.
Manufacturing takes lead
Meanwhile a study by the Engineering Employers Federation has concluded that investing in occupational health helps cut absence rates.
A survey of 600 firms found a "clear link" between addressing sickness absence and improving business performance.
EEF Chief Medical Advisor Professor Sayeed Khan said: "Those companies who still put this issue in the `too difficult' tray would do well to sit up and take note of the very real benefits they would reap from tackling the problem."
The survey found manufacturing firms invested most in occupational health, with 65% of firms providing some form of service. This is more than double the national average estimated by the Health & Safety Executive (HSE) of 25-33%