A new study has found that women who have cardiac arrests in public are less likely to receive CPR than men. In fact, they are also more likely to die from the cardiac event than their male counterparts, the study from the University of Pennsylvania suggests.

Researchers studied 19,331 cardiac events that took place in the United States and Canada. Using data from the Resuscitation Outcomes Consortium, they looked at cardiac events and trauma that happened to people in public locations.

They found that men were 1.23 times more likely to receive CPR from a bystander than women. Men received CPR 45 percent of the time, but women only did 39 percent of the time. Men were also twice as likely to survive a cardiac event as women.

When the researchers looked at cardiac events that took place in the home, however, they found no significant difference between men and women: 35 percent of women received CPR following an event, compared to 36 percent of men. So why the big difference when women are out in public?

An explainer on how to do CPR. Further instructions can be found on the UK's National Health Service's website.

Researchers at the university suggest that the reason could be that people are less comfortable giving CPR to a woman they don't know than to a man. Bystanders may be more "squeamish" about performing CPR on women.

Discussing the results at an American Heart Association conference, the study's authors said that the difference could simply also be down to the reluctance of rescuers to remove a woman's clothing in order to get better access to her sternum, or an unwillingness to touch her breasts in order to perform CPR.

“This is not a time to be squeamish, because it’s a life-and-death situation," said study co-leader Dr Benjamin Abella, according to the Associated Press.

Besides: "You put your hands on the sternum, which is the middle of the chest. In theory, you're touching in between the breasts."

The authors also think that women might be less likely to receive CPR because CPR training mannequins are generally shaped like male torsos. As a result, people may feel less well-equipped to perform CPR on women because of the difference in body shape.

“By uncovering this disparity, we’ll be able to think about new ways to train and educate the public on when, why, and how to administer bystander CPR, in order to help save more lives – of both men and women," study co-leader Audrey Blewer said in a statement.

“Regardless of someone’s gender or how their body is shaped, delivering bystander CPR during cardiac arrest is absolutely critical, as it has been proven to double and even triple a victim’s chance of survival."