The report, by Nicholas A. Christakis, M.D., Ph.D., M.P.H., of Harvard Medical School, and Paul D. Allison, Ph.D., of the University of Pennsylvania, is the first to measure a link between a spouse's hospitalization and increased mortality of their partner across a comprehensive range of spousal diseases. The findings, says Christakis, were striking. "When a spouse is hospitalized, the partner's risk of death increases significantly and remains elevated for up to two years," he notes. The study is published in the Feb. 16, 2006, issue of the New England Journal of Medicine.

"This highly innovative study - in an enormous sample of older people - demonstrates yet another important connection between social networks and health," says Richard M.Suzman, Ph.D., Associate Director of the NIA for Behavioral and Social Research. "We don't yet know the full extent to which social networks affect health. We need to explore the mechanisms behind the stresses associated with these hospitalizations as we look for ways to protect people when their central relationships are disrupted."

Christakis and colleagues studied more than half a million couples over 65 years old who were enrolled in Medicare from 1993 through 2001. Over that period, the study found that, overall, having a sick spouse is about one fourth as bad for a partner's health as having a spouse actually die. Some spousal diseases, such as hip fracture or psychiatric conditions, were nearly as bad for partners as it would be if the spouse actually died. The period of greatest risk is over the short run, within 30 days of a spouse's hospitalization or death, the researchers noted, when the risk of death upon a spouse's hospitalization is almost as great as that when a spouse dies. The mortality risk increased with age and, for women of a hospitalized husband, with poverty.

The illness responsible for the spouse's hospitalization also matters. For example, among men with hospitalized wives, if their wife is hospitalized with colon cancer, there is almost no effect on the husband's subsequent mortality. But if the wife is hospitalized with heart disease, the risk of death for a husband is 12 percent higher compared to the wife not being sick at all. If one's wife is hospitalized with psychiatric disease, a partner's risk of death is 19 percent higher. And if one's wife is hospitalized with the principal diagnosis of dementia, mortality risk for the husband is 22 percent higher. Similar effects are seen in women whose husbands are hospitalized.