We hear a lot about reducing the cost of sickness absence - both real and imagined - but rather less about the impact of staff struggling into work when they would be physically or psychologically better off staying at home.
But according to a new report from the UK-based Work Foundation, the cost of sickness presence - so-called 'presenteeism', could actually exceed the estimated £13bn annual bill for sickness absence.
The report, based on a study of 510 employees at health insurance group, Axa PPP, found that over a four-week period, almost half of staff (45 per cent) had worked while unwell, compared with fewer than one in five (18 per cent) who had taken time off. Those who had time off sick were also more likely to work when ill, the report found.
Dr Katherine Ashby, lead author of the report, said that higher levels of sickness presence were linked to higher levels of absence, lower levels of self-reported psychological wellbeing and higher levels of work-related stress.
The factors influencing sickness presence included personal financial difficulties, work-related stress, and perceived workplace pressure.
In contrast, staff with lower levels of perceived workplace pressure, less work-related stress and fewer personal financial difficulties reported fewer days of sickness presence.
"Like sickness absence, sickness presence can be a symptom of underlying issues so it's important to identify and tackle these underlying issues in sickness presence in the same way it is sickness absence," she explained.
"We think employers may be at risk of underestimating employee health and missing signals by focusing on sickness absence alone."
The report found that many employees felt under pressure to come into work when unwell in order to 'prove' their illness to their manager and/or team. Such negative perceptions of attendance management were also linked to the perceptions that managers and the organisation did not care about employees' health and wellbeing.
In this way sickness absence management was perceived to be driven by the financial concerns of the organisation and line managers, rather than focused on the best interests of the employee.
Yet some employees viewed the pressure to come to work when as being a consequence of other employees abusing the company's sickness absence and sick pay system.
They felt that this abuse of the system by others who 'pulled sickies' and took sick leave when it was not justified had led to the strict system, which put pressure on those who were ill to prove their ill health.
"Organisations need to be aware that low levels of sickness absence may not tell the whole story," Katherine Ashby said.
"Successfully tackling the underlying causes of sickness presenteeism could improve employee wellbeing and reduce both sickness presence and sickness absence."