Lower paid NHS staff and junior workers are more likely to go off sick than senior colleagues, according to a new report.
Those working in parts of England with high deprivation are also significantly more likely to report absence than staff working in more affluent areas.
There are wide variations around the country when it comes to NHS sickness absence, with some organisations having a rate of 1.6 per cent and others reporting 6.8 per cent.
Healthcare assistants have the highest average rate of absence - 6.5 per cent - followed by ambulance staff at 6.3 per cent, and nurses, midwives and health visitors (5.2 per cent).
The North East was found to have the highest sickness rate on average, with the lowest seen in London.
It says the NHS could save £290m if sickness absence rates were reduced to the lowest 25%.
Staff sickness absence in the NHS is estimated to cost £1.7bn a year, and is higher than in the private sector.
Deprivation and staff pay grade account for 61 per cent of the variation in hospital trust absence and 38 per cent in primary care trusts, according to the study.
Experts are unclear exactly why deprivation and pay scale influence absence rates so much, although “morale and ability to control one’s work” may play a role for those who are lower paid.
However, the remaining variation is down to “systematic differences” between NHS organisations and the way they manage, support and motivate their staff, the study says.
Factors may include how long-term sickness absence is managed by an organisation, and whether musculoskeletal conditions could be eased by better training on the right way to lift patients or use equipment.
If people are off with stress, managers should look at ways of dealing with their workload, it suggests.
The estimated direct cost of sickness absence in the NHS ranges from less than £700 to just over £2,700 per full-time member of staff.
Andy McKeon, managing director of health at the Audit Commission, said: “Managers need to be realistic about what they can achieve and accept that some staff, such as frontline workers who deal with sickly patients all day, are likely to have more days off sick than, for example, those without direct patient care responsibilities.”