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%) reported high emotional exhaustion, one in 10 (10%) said they experienced high de-personalisation and 17% felt low personal accomplishment - the three recognised measures of burnout.
A quarter (26%) expressed dissatisfaction with their job, a similar proportion (25%) were equally dissatisfied with their work schedule flexibility, and a third said they intended to leave their current job (33%).
Researchers found 12 hour plus shifts were more common in certain countries, with more than a third (36%) of respondents in England, four out of five (79%) in Ireland, and 99% in Poland, working this shift length.
More than one in four of the entire sample (27%) 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%) were women.
The most common shift length was eight or fewer hours (50%), while almost a third (31%) worked 8 to 10 hours, 4% worked 10 to 12 hours and 14% worked 12 to 13 hours.
Some 1% 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.
A Department of Health spokesman said: "NHS staff are our greatest asset and it's vital that employers make sure staff get the care and support they need. We do not expect our staff to work unsafe hours.
"That's why we've asked NHS Employers to help Trusts to keep their workforce well and NHS England is investing £5million in a new staff health and wellbeing initiative. We are committed to making sure we have enough staff to meet patient needs seven days a week."