Sickness absence for staff in the NHS has risen for the first time in four years, according to a survey of 76 NHS organisations across Britain.
NHS sickness absence rates rose from 4.6% in 2005-06 to 5%, reversing the recent trend of improving absence levels.
The figure is the second highest rate recorded since the survey started 12 years ago.
The estimated average cost of sickness absence for each NHS organisation surveyed is almost £5m, or an average of £1,750 per full-time equivalent employee.
The survey, by research provider Capita Health Service Partners, said it was not clear why absence levels had increased.
However, the rise in the NHS will disappoint the government, which has set targets for reducing sickness absence across the public sector.
NHS staff turnover has continued to fall to 11% for 2006-07 and is now at its lowest recorded level.