Hospitalization of a spouse due to dementia raises a partner's risk of dying by 22 percent for a husband and 28 percent for a wife, according to a study appearing in the Feb. 16 New England Journal of Medicine.

The rise exceeded the increase linked to hospitalization for several types of cancer, heart disease, stroke, lung disease and serious fractures. It was the largest seen for any health condition except a psychiatric illness, which raised a female partner's risk of death by 32 percent.

"For years, the Alzheimer's Association has worked to build awareness that the impact of Alzheimer's extends far beyond those diagnosed with the disease," says Sam Fazio, Ph.D., Alzheimer's Association director, medical and scientific affairs. "This study clearly documents the devastating effect that hospitalization or death from dementia has on a partner."

According to study results, death of a partner from any cause increases risk of death, on average, by 21 percent for men and 17 percent for women.

The study, believed to be the largest ever to look at the effect of spouse illness and death on partner health, followed 518,240 couples between the ages of 65 and 98 who were enrolled in Medicare. Beginning in 1993 and continuing for nine years, the investigators documented hospitalizations and deaths due to a range of health conditions.

They found when a spouse is hospitalized or dies, the partner's risk of death increases significantly. Although the period of greatest vulnerability occurs within the first 30 days, risk remains elevated for up to two years.

The study did not identify reasons for the increased risk. The authors point out that spouse illness or death deprives a partner of social, emotional, economic and practical support. In the aftermath, partners may fall into less healthy habits, such as poor eating or excess drinking. Stress and lack of social support may also produce physical effects through an impact on the immune system.