Employers remain unaware of the causes of sickness absence and their current absence levels, according to research by Aon Hewitt. The Aon Hewitt Benefits and trends survey, which polled 185 employers in the UK representing a combined workforce of 650,000 employees globally, found one-third (32%) of respondents did not know how many days employees are absent through ill-health annually. Of those that could give a figure, 60% were not very confident of its accuracy.