Married adults who undergo heart surgery are more than three times as likely as single people who have the same surgery to survive the next three months, according to a new study.

The lead author of the study, Ellen Idler, a sociologist at Emory University, said it showed “a dramatic difference in survival rates for single people”.

She said the researchers “found that marriage boosted survival whether the patient was a man or a woman”.

The study, published in the March issue of the Journal of Health and Social Behaviour, showed that the strong protective effect of marriage continues for up to five years following coronary artery bypass surgery. 

Overall, the danger of mortality is nearly twice as great for unmarried as it is for married patients about to undergo the surgery.

“The findings underscore the important role of spouses as caregivers during health crises,” Idler says. “And husbands were apparently just as good at caregiving as wives.”

Repeated studies have shown link between marriage and longer life and better health. As far back as 1858, medical statistician William Farr observed that marriage protected against early mortality in France. 

The evidence continues to mount that the widowed, never married, and divorced have higher risks of mortality. Much of the research, however, has looked broadly across populations during an entire lifespan, or relies only on medical records.

“We wanted to zero in on a particular window of time: a major health crisis,” Idler says, “and we wanted to add the in-person element of patient interviews, in addition to the full record of their medical history and hospitalisation.”

More than 500 patients undergoing either emergency or elective coronary bypass surgery were involved in the study. All of the study subjects were interviewed prior to surgery. Data on survival status of the patients were obtained from the National Death Index.

The researchers were unable to say conclusively why married patients tended to perform so much better than their single counterparts in the three-month survival rate.

However interviews with the patients suggested some possible answers.

“The married patients had a more positive outlook going into the surgery, compared with the single patients,” Idler says. “When asked whether they would be able to manage the pain and discomfort, or their worries about the surgery, those who had spouses were more likely to say yes.”

Patients who survived more than three months were approximately 70 percent more likely to die during the next five years if they were single. An analysis of the data showed that smoking history accounted for the lower survival rates in the single patients over this longer term.

“The lower likelihood that married persons were smokers suggests that spousal control over smoking behavior produces long-term health benefits,” Idler says.

When it comes to healing hearts, marriage may be powerful medicine, but it’s in increasingly short supply, Idler says, which does not bode well for aging baby boomers.

Barely half of U.S. adults are currently married, the lowest percentage ever, according to the Pew Research Center.