Judith and Gerson Leiber were married for 72 years. She was a handbag designer…he was an artist. According to their New York Times obituaries, she was 97, and he was 96 when they died of dual heart attacks—just a few hours apart, earlier this year.

The story would be astonishing…if it were not so familiar. Spouses who die in quick succession often make the news, whether they were famous in life or not.

Singers June Carter and Johnny Cash died within four months of each other—she from heart surgery complications and he from diabetes. The parents of football star Doug Flutie died of heart attacks less than an hour apart, according to their son. Such stories could be dismissed as mere coincidences. But social scientists say there’s something real at work here.

They call it “the widowhood effect”—the increased risk for death we face when a spouse dies. That risk is elevated by more than 50% in the first month after the death, according to the largest studies on the phenomenon.

To learn more, Bottom Line Health spoke with Felix Elwert, PhD, a sociologist and leading authority on widowhood.

How strong is the evidence that the widowhood effect is real? It’s one of the strongest findings we have on the connections between social factors and health. The link between marriage and death was first noticed back in 1858 by William Farr, a pioneering social scientist.

More recently, it’s been confirmed by numerous large studies using varying methodologies. These studies have sorted out whether the link is merely an association—explained, for example, by the fact that spouses often share health-threatening habits or circumstances, including advanced age—or a matter of cause and effect. The evidence is strong that this is indeed a cause-and-effect relationship, at least in part. Losing a spouse does increase your risk for death in the near future.

How big is the risk and how long does it last? As mentioned earlier, the risk spikes at least 50% above the normal death rate in the first month after the spouse’s death. It then declines but remains higher than normal for years afterward. The overall increased risk approaches 20% over three or more years.

Do men and women have differing levels of risk? Many people are surprised to learn that the biggest studies find no meaningful differences in death rates between recently widowed men and women—though conventional wisdom assumes men get more health benefits from marriage and thus face greater risks when a spouse dies.

However, the reasons for increased death rates vary between bereaved men and women, based on research by sociologist Linda Waite and colleagues at University of Chicago. In the case of an older man, for example, the loss of a spouse often means the loss of a primary caregiver—the person who cooks his meals, arranges his social life and makes sure he takes his pills and keeps his doctors’ appointments.

Women may be better equipped to do those things for themselves but may suffer more for financial reasons—because in most older heterosexual couples, it’s still true that men earn more than women over a lifetime. When men die, there’s typically a reduction in pension and Social Security benefits to the surviving spouse.

Does grief itself play a role? The sharp spike in deaths immediately after a spouse dies certainly suggests that the strain and shock of that loss, both of which are key elements of grief, do play roles. The days and weeks after a death can be especially stressful and disorienting. It is reasonable to assume that those disruptions can have all kinds of negative effects on health. But we do not have the psychological data to know to what extent those stresses make a direct contribution to deaths we see among widows and widowers.

Is there any group at decreased riskand, if so, what could we learn from them? In at least one ethnic group, African-Americans, researchers have failed to find the widowhood effect. That has led to speculation about what might protect black men and women. One factor could be that elderly African-Americans are much more likely than whites to live with other adult relatives—40% versus 20%. That may help the recently bereaved stay socially connected, which in turn can have health benefits.

We also know that African–American wives are more likely to work and African-American men are more likely to help out around the house than their white counterparts. This means that each spouse may be less specialized in his/her marriage roles and more able to cope when a spouse dies.

Does the spouse’s cause of death have any influencethat is, are you more at risk if your spouse died of cancer than if he/she died from Alzheimer’s? The increased risk is seen after a spouse dies from almost any cause, ranging from cancer to a car crash to heart disease. There are two exceptions, though—there’s no apparent increase in death among those whose spouses die of Alzheimer’s disease or Parkinson’s disease.

One theory is that deaths from Alzheimer’s or Parkinson’s have less impact because they are expected for years in advance. Another is that people with these conditions stop contributing to their spouses’ health and well-being long before their deaths—meaning any adverse effects have already occurred.

Are people who lose a spouse likely to die in any particular wayfrom heart attacks, for example? While the media tend to focus on serious conditions such as “broken heart syndrome”—a life-threatening heart problem sometimes seen in grieving people—research finds that deaths from all causes rise after the loss of a spouse.

There are, however, especially large increases in deaths from sudden events such as accidents as well as those from infections and certain chronic conditions, such as diabetes, that require careful daily management, according to our research published in American Journal of Public Health.

There’s no single explanation for these deaths, but the pattern suggests that the widowhood effect in these cases is driven by the loss of social connection and daily support that had been provided by the spouse. For example, a spouse could call the ambulance if the other falls and breaks a bone, but a widowed person might well die of the same fracture because help is delayed.