MAY 18, 1998 VOLUME 5, NUMBER 46
With improvements in medical care, nutrition and sanitation, we have steadily lengthened life for most seniors. It has been less clear, however, whether the quality of life has been improved at the same time.
In this youth-oriented culture, the image of aging is frequently tied to chronic illness and debility. Two recent studies attempt to determine whether longer life can mean better life, and whether chronic illness can be linked to shortened life expectancy.
In a study conducted by researchers at Stanford University, college graduates were followed for a 30-year period to determine whether longer life could be equated with disability. Subjects of the study were analyzed for disabilities twenty years after college graduation (at an average age of 43) and again several times over the next thirty-two years. They hoped to determine whether those subjects who died at older ages were chronically ill for longer or shorter periods at the end of their lives.
Not surprisingly, the researchers found that those subjects who smoked, avoided exercise and were overweight all tended to die younger. Ranges were assigned to those three risk factors, and each subject was categorized as high risk, moderate risk or low risk based on their smoking, exercise and weight.
Not only did the low-risk group tend to live longer, they also suffered fewer disabilities during the last year and two years of their lives. Among the subjects who died during the study period, the high-risk group showed about twice the level of disabilities found in their low-risk colleagues.
Similarly, among the study participants who were still living at the end of the reported data period (at an average age of 75 years) the low-risk group was in substantially better health. Again, they were about half as likely to suffer disabling conditions as their high-risk peers. New England Journal of Medicine, 4/9/98.
The Stanford study supports the so-called “compression of morbidity” hypothesis. According to that theory, health improvements which increase longevity should increase the average age of onset of disability even more dramatically. In other words, lengthening life should also improve the quality of life, on average.
A second recent study, conducted by Yale researchers, looked at a related issue. Do demented patients, or patients who are unable to perform activities of daily living without assistance, tend to die more quickly than their more independent peers?
To determine the answer, all patients over age 70 admitted to Yale’s hospital for a three-week period were evaluated. They were given cognitive tests and evaluated for functional disabilities (such as limitations on their ability to feed, clothe or bathe themselves, or to use the telephone, cook or handle finances). Their vision and hearing were also checked, as was their susceptibility to depression.
Among the patients with cognitive deficits, the risk of death within two years was almost three times that of patients without dementia. For patients with functional deficits, the risk of death within two years was about doubled. There were also slight increases in the risk of death for those with vision or hearing losses and for those suffering from depression. Journal of the American Medical Association, 4/15/98.
Of course, it is easy to observe that dementia, functional limitations and other health problems are more likely to appear in patients who are sicker on admission to the hospital (and thus less likely to survive). This undoubtedly accounts for some of the increase in mortality for those patients. Still, researchers attempted to correct for this bias, and the study shows a strong correlation between functional and mental status and risk of death.