NURSING shifts of 12 hours or more are linked to heightened risk of burnout and job dissatisfaction, according to an international study of more than 31,000 hospital nurses.

A survey of nurses in 12 European countries found such long shifts were particularly common in England and Ireland, research published in the online journal BMJ Open found.

Across all the countries, around one in four (27 per cent) reported high emotional exhaustion, one in 10 (10 per cent) said they experienced high de-personalisation and 17 per cent felt low personal accomplishment - the three recognised measures of burnout.

A quarter (26 per cent) expressed dissatisfaction with their job, a similar proportion (25 per cent) were equally dissatisfied with their work schedule flexibility, and a third said they intended to leave their current job (33 per cent).

Researchers found 12 hour plus shifts were more common in certain countries, with more than a third (36 per cent) of respondents in England, four out of five (79 per cent) in Ireland, and 99 per cent in Poland, working this shift length.

More than one in four of the entire sample (27 per cent) had worked overtime on their last shift.

The study was led by the University of Southampton, with the authors suggesting that health leaders should question whether shifts longer than eight hours were appropriate.

''Our results provide the basis for managers and nurses alike to question routine implementation of shifts longer than eight hours, and the use of overtime that is associated with poor nurse outcomes under any shift length, suggesting that overtime may not be a useful strategy to cope with nursing shortages,'' they said.

The survey included a total of 118 questions relating to the demands and experience of the job itself along with the length of shifts worked.

The average age of the respondents was 38 and most (92 per cent) were women.

The most common shift length was eight or fewer hours (50 per cent), while almost a third (31 per cent) worked 8 to 10 hours, 4 per cent worked 10 to 12 hours and 14% worked 12 to 13 hours.

Some 1 per cent worked more than 13 hours.

The study saw nurses in Belgium, England, Finland, Germany, Greece, Ireland, Netherlands, Norway, Poland, Spain, Switzerland and Sweden questioned.

''In the context of austerity measures leading to cuts in spending on public services in Europe, it is particularly important for policymakers and managers to have good evidence on which to base decisions on hospital nurse work hours to ensure that the well-being of workers and the quality of care is maintained and nurses are retained in practice,'' the authors added.