The survey of more than 31,000 nurses in 12 European countries, including Ireland, found that working 12 hours or more is associated with a heightened risk of burnout and job dissatisfaction.
Long shifts were particularly common in Ireland and England, according to the research published in the online journal BMJ Open.
Responding, the Irish Nurses and Midwives Organisation (INMO) argued that the main factors linked to burnout were staffing levels and workloads.
However, the survey on 12-hour shifts found that more than one in four nurses (27%) reported high emotional exhaustion, while 10% said they experienced high depersonalisation and 17% low personal accomplishment — the three dimensions of burnout.
Around one in four expressed dissatisfaction with their job; while a similar proportion were equally dissatisfied with their work schedule flexibility; and a third planned to leave their current job. Job dissatisfaction increased to 40% among those clocking up shifts of 12 hours or more compared to those working shifts of eight hours or less, while the intention to leave rose to 30%.
The study was led by the University of Southampton, with the authors suggesting that health bosses should question whether shifts longer than eight hours were appropriate.
Nurses in Belgium, England, Finland, Germany, Greece, Ireland, Netherlands, Norway, Poland, Spain, Switzerland and Sweden were questioned. The average age of the nurses was 38 and almost all (92%) were women.The most common shift length was eight hours or less (50%); while almost a third (31%) worked eight-10 hours; 4% worked 10-12 hours and 14% worked 12-13 hours. Some 1% worked more than 13 hours.
More than three-quarters (79%) of the nurses in Ireland said they worked shifts of 12 hours or more — 39% of nurses in England said they worked this shift length and 99% in Poland.
More than one in four of all the nurses questioned said they had worked over-time on their last shift.
INMO director of industrial relations, Phil Ni Sheaghdha, said their members would say “categorically” that what was causing them to leave and seek jobs in the private sector or abroad was the extraordinary workloads and continuous staff shortages.
Ms Ni Sheaghdha said many nurses worked a 12-hour shifts as part of their weekly roster, particularly those on night duty, and there were advantages because of the knock-on effect on childcare and parking costs.
The authors of the BMJ study said employers needed to be aware of the potential effects of burnout, which include a heightened risk of making a mistake; poorer quality of care; compromised wellbeing; and increased absenteeism and high staff turnover.
Meanwhile, Brendan Mills, co-ordinator of the Homeless Initiative with Ag Eisteach, in Cork, a registered charity that provides training for frontline staff in the homeless sector, has warned that an increasing number of staff were facing burnout.
“Staff in the homeless sector are literally facing a conveyor belt of people in crisis one after the other,” said Mr Mills, who sat on the board of the Cork Homeless Forum for 11 years.