Female shift workers risk disability retirement

NEW YORK (Reuters Health) - Women seem to be more vulnerable than men to the rigors of shift work. In a long term follow-up study, researchers found that shift-working women but not shift-working men had a moderately increased risk of disability.

"It was a surprise to find that shift-working women but not men had an increased risk of disability," Dr. Finn Tüchsen, senior researcher at National Research Centre for the Working Environment, Copenhagen, told Reuters Health.

"This study is the first to report this difference so we do not know if it is related to specific diseases, employability or gender-specific administrative practices. We can only recommend that other studies look into this," the researcher said.

The finding, published in the journal Occupational and Environmental Medicine, are based on 3,980 female and 4,025 male employees participating in a large health and work study launched in 1990 called the Danish Work Environment Cohort Study. During the next 15 years, investigators collected information about the subjects' workplace environment, work patterns, health, and lifestyle.

By June 2006, more women than men (253 versus 173) had been forced to retire early because of ill health and had been granted a disability pension, the investigators report.

After adjusting the data for factors that could influence disability, they found that women were more likely than men to receive a disability pension.

Moreover, women who were shift workers were 34 percent more likely than women who worked regular 9-to-5 jobs to be granted a disability pension. However, men who were shift workers were no more likely than day workers to retire early due to disability.

In this study, shift work was defined as working irregular hours, evening shifts or night shifts.

Shift work has been linked to heart disease, breast cancer, ulcers, sleep disturbances, accidents and pregnancy complications, Tüchsen and colleagues note. "It is therefore not surprising if the incidence of disability retirement is higher among shift workers, but we have no knowledge about why women should be more vulnerable to shift work than men as our results suggest."

"If other studies confirm that shift work carries an increased risk of more than 30 percent for women, then gender-specific preventive strategies are needed," Tüchsen told Reuters Health.

SOURCE: Occupational and Environmental Medicine, January 15, 2008.