The fact that night-time work is strenuous for health has been observed in many different studies. It has also been observed that shift work is worse for women than for men. The reason for this is now being investigated by researchers at the Stress Research Institute – so that a solution to the problem can be found.

Today, about every fourth employee in Sweden is employed in shift work – landing us firmly amongst the EU countries with the most shift workers. More than half of all those who work irregular hours throughout the day and week are women and many of those are working in health care.

Women affected more negatively than men

Long-term shift work often puts strains on health and there are a large number of scientific studies that show how our working hours can increase the risk of diseases such as diabetes and some cancers. It is also known that women’s health and sleep are affected more negatively by working shift work than men’s. What these differences depend on however, is the need for further investigation. Therefore, a group of researchers at the Stress Research Institute and Karolinska Institutet will now examine large-scale longitudinal data to identify the factors that affect the ability to cope with shift work.

“It’s complicated to compare men’s and women’s shift work, because they work largely in different sectors. We are not the first to investigate the differences, but we will try to avoid the problems found in several previous studies”, says Philip Tucker, Guest Researcher at the Stress Research Institute, who will head the study.

Philip Tucker

They have the assistance of data from two long-term studies: SLOSH, which is representative of the Swedish labour force and LANE, which specifically follows nurses during the last year of their education and the first three years in the profession, when many have begun shift work. The data from LANE thus gives a picture of how health in a strongly female dominated profession is affected by shift work compared to working daytime only.

“It is interesting to investigate what it is that changes when you start shift work. Many nurses work in similar working environments and in the long term, we hope to identify potential interventions that can improve the working situation for shift workers in health care”, says Philip Tucker.

Human needs neglected

Nurses often have the hardest shift schedules, with at least two shifts per day. In some schedules, the intervals between the shifts are so short that it is impossible to find time for both the different needs in daily life and to get enough sleep before the next shift begins.

“Many shift workers like to consolidate their work weeks in order to have longer periods of free time. The disadvantage to this is that there is not enough time for rest and recuperation between work. We must all eat and sleep and, of course, we also have other things to do outside of work. Something needs to be sacrificed”, he states.

Often it is sleep that is sacrificed – and sleep is a key factor in maintaining health. Because many nurses alternate between working night and day, the body’s internal clock is also disturbed.

“The consequence is that the body is struggling to adjust to being awake at night – without really succeeding. If you alternate between working day and night, it’s best to keep the body’s internal clock on a day schedule. At the same time, it means that night shifts can be challenging”, says Philip Tucker.

The effect of inequality in the home

The health differences that have previously been observed between male and female shift workers can thus partly be explained because it is more common for women to work the most demanding shift configurations. But there are also other factors that can play a part, such as stress levels in the workplace and family responsibilities.

“Even though Sweden is the most gender equal country in the world, we know that it is still not completely equal in most families. Women carry a heavier load in regards to children and household duties – we will take this into account when we examine the differences”.

What do you hope the study will lead to?

“First and foremost, we will try to identify which factors cause women to be more negatively affected by shift work. Then we can aim to reduce this difference. Our focus is on improving the working situation for women who do shift work, but it is very possible that our results will also work well for male shift workers”, says Philip Tucker.

Have you ever worked shift work?

“Not on a regular basis, as maybe I should have done. My experiences are from simulated shift work for study purposes. Even though I and my research colleagues design shift schedules, we completely ignored our own advice!”

Text: Linnea Bolter