According to a Danish study, 24 percent of people who return to work after a heart attack leave their job within a year.

Published online Oct. 4 in the Journal of the American Heart Association, the study revealed 91 percent of people returned to work within a year of having their first heart attack. However, 24 percent of the more than 20,000 patients who returned left their jobs and were supported by social benefits within a year of resuming work.

“The ability to remain employed following a heart attack is essential to maintaining one’s quality of life, self-esteem, emotional and financial stability, so our findings carry critical implications not only for Danish patients but, perhaps more importantly, for people who live in countries with less advanced social welfare systems than Denmark,” lead author Laerke Smedegaard, MD, a medical doctor at Herlev & Gentofte University Hospital in Hellerup, Denmark, said in a press release.

The study included patients aged 30 to 65 who suffered their first heart attack between 1997 and 2012. Both ends of the spectrum—30 to 39 years old and 60 and older—were associated with the highest rates of work dropout. This is particularly alarming for the younger group, the authors pointed out, because they should have many productive work years remaining.

People with higher income and education were more likely to remain employed, while those with heart failure, depression or diabetes were less likely to stay employed.

The researchers were unable to measure whether patients left their jobs voluntarily or involuntarily, although they pointed out these people most often received sick leave benefits.

“When evaluating a heart attack patient’s quality of life and functional capacity, simply returning to work after a heart attack isn’t enough,” Smedegaard said in the release. “Our findings suggest that cardiac rehabilitation after a heart attack should also focus on helping people maintain their ability to work in the long term.”