MONDAY, Sept. 10, 2001 (HealthDayNews) -- If there were a genetic test for Alzheimer's disease, would you take it?
Nearly eight in 10 American adults would if it were 100 percent accurate, says a new survey, If it were wrong even one in 10 times, the survey shows the proportion who would be screened drops to less than five in 10.
The telephone survey, which appears in the latest issue of the journal, Health Affairs, was done by Harvard University researchers who wanted to explore American's attitudes toward genetic testing for Alzheimer's disease. A gene test does exist for the degenerative brain disorder, but experts don't recommend it because it's not especially accurate, and there's nothing that can be done to prevent the disease in those who test positive. Alzheimer's has no cure yet.
Alzheimer's affects about 4 million Americans, a number that is predicted to grow as the population ages.
"People value information, even if there's nothing in terms of immediate health or medical things they could do" with it, says lead study author Peter Neumann, a decision sciences expert at the Harvard Center for Risk Analysis.
Neumann and his colleagues asked 314 people, whose average age was 43, whether they would be willing to undergo a test for a hypothetical Alzheimer's gene if the results were always correct, and how much they would pay for that test. Seventy-nine percent said they would opt for the screening, as long as it cost $324 or less.
But when told the test would be 90 percent accurate -- meaning one in 10 results would be incorrect -- only 45 percent said they'd undergo the screening. Their willingness to pay fell, too, to $170 per test, on average.
People with a family history of Alzheimer's and people who'd taken care of someone with the illness were most likely to say they'd want the gene test. Older people also were more likely to say they'd take a test.
Those who rejected screening cited fear of living under the shadow of the disease, and the fact that there's no way to treat or prevent it yet. Only about a third of survey participants said they were worried or very worried that their tests results might be abused by an employer or insurance company.
When asked what they would do if their screening came back positive, 84 percent said they would write a living will. A little more than 80 percent said a positive result would encourage them to spend more time with their family, and about 74 percent said they would get their finances in order.
Katherine Schneider, senior genetic counselor at the Dana-Farber Cancer Institute in Boston, says the findings aren't surprising given earlier surveys about genetic testing. "I think that in attitude studies across the board, the majority of people are interested in testing," says Schneider, who is president-elect of the National Society of Genetic Counselors.
But when it comes to screening, interest rarely translates into action. "With Huntington's [a deadly, single-gene disease for which testing is available] and in cancer, when you actually roll out the red carpet and offer testing, nobody wants to come in. It's easier to say 'Absolutely, I'd be interested,' than to actually face it," Schneider says.
Schneider says fear of a positive result is the main reason people don't opt for genetic testing, and math compounds the situation. she says few genetic tests are like a light switch, where the probability of getting sick is 100 percent. Schneider says that frustrates the job of genetic counselors who have to explain risks and odds, a problem that will only grow thornier with the daily discovery of new disease genes.
What To Do
The Alzheimer's Association says researchers so far have identified four gene mutations associated with the disease, including three that appear to predispose carriers to an early-onset form of the condition.
While you might not be able to prevent Alzheimer's, you can improve your odds of healthy aging, experts say. Eating right, getting plenty of exercise and keeping mentally fit can reduce your chances of physical problems and even mental decline.
To learn more about Alzheimer's disease, try the Alzheimer's Association or the Alzheimer's Disease Education & Referral Center.
For more on genetic testing, visit the National Society of Genetic Counselors.
