More than one in five UK employees who took sick leave in the past year admit they could have gone into work if they had really wanted or needed to.
A survey of 250 employers and their staff, by consultancy Watson Wyatt, also shows that 40% of employees would be less likely to take days off sick if it meant they would not be paid for the days that they were absent.
More than three-quarters of employers have no firm understanding of, or control over, the cost of absence to their business.
And more than a quarter only formally start to manage employee absenteeism after four weeks.
David Cross, head of healthcare and risk consulting at Watson Wyatt, said: “If companies realised what absenteeism was costing them in real terms, rather than the usual woolly estimates, the issue would be higher up the agenda.”
The survey also shows that more than a quarter of employees feel stress at work contributes to at least one of their absences in the past year.
“Given the increasing requirements on employers to reduce workplace stress, many employers will wish to reconsider their approach to such issues,” said Cross.