NHS workers took on average 9.5 sick days last year - more than double the national average - but hospital doctors took only 2.8 days.

New figures for 2012-13 from the Health and Social Care Information Centre (HCSIC) show a slight increase in the number of days taken off sick since last year, across more than one million NHS staff members.

The highest number of absences was among ambulance workers, who took on average 14.7 days off sick per year.

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Sue Covill, director of employment services at the NHS Employers organisation said that the slight increase was a reflection of "the significant pressures of a long winter, organisational restructuring and challenging expectations" on the health service.

The latest Office for National Statistics figures on sick days indicate that the average worker took 4.5 days sick leave in 2011, although more recent estimates suggest that figure could now be even lower.

Across the NHS, more than 4 per cent of staff were ill on an average day. Sickness absence was highest among lowest paid staff, HSCIC said.

"Employers will be exploring in detail why sickness absence has risen slightly and exploring how best to support their staff in the light of challenges faced," Ms Covill said. "Major staff groups, including nurses, are taking less sick-leave now than at the beginning of the decade, and systems to support their health and wellbeing have undeniably improved. The simple fact is the NHS environment has become more challenging for everyone, making supportive approaches essential to mitigate the pressures and help staff work within them."