Debate flaring up over use of dementia screening

Organizations that issue screening guidelines should consider seriously whether physicians should discuss dementia with patients at age 50 and initiate annual dementia screening in those older than 75, according to a perspective piece published last month in Alzheimer's & Dementia, the Journal of the Alzheimer's Assn.

The authors hope for a positive response that will lead to an increase in the number of Alzheimer's patients able to access treatment at the disease's early stages, when it is most effective and when patients are able to make the necessary arrangements for the time they no longer can care for themselves. Also, patients whose dementia is caused by other reasons could have those reasons addressed.

"There are social and medical benefits. I consider it worth it," said J. Wesson Ashford, MD, PhD, lead author and senior researcher at the Stanford/VA Alzheimer's Research Center of California.

Those who work closely with dementia patients praised the paper for increasing the possibility that screening would become a reality.

"I'm 100% for it," said Mark Sager, MD, director of the Alzheimer's Institute at the University of Wisconsin in Madison. "We cannot wait until the diagnosis is obvious."

The reasons why

Experts say screening has the possibility to improve outcomes not only for individuals but also for their families. Relatives could access social support sooner, and, because Alzheimer's has a significant genetic component, these people also could take steps, such as improving their diet, to attempt to prevent the disease from developing.

For example, a study published online in the Annals of Neurology found that the Mediterranean diet, which long has been associated with a lower risk of cardiovascular disease, also reduces the risk of Alzheimer's.

"Screening for Alzheimer's is essential and extremely worthwhile," said Stanley J. Birge, MD, associate professor of medicine in the geriatrics and nutrition division at Washington University in St. Louis School of Medicine. "There's so much we can do for the patient who does have Alzheimer's. And we can work with the family, which is the other patient."

Screening for dementia, however, is extremely controversial. Most organizations that issue related screening guidelines agree that early detection is important. But widespread screening of those who are asymptomatic has never gotten an endorsement. The U.S. Preventive Services Task Force issued a June 2003 statement that there was insufficient evidence for or against the screening of older adults. The American Academy of Neurology recommends screening only when dementia is already suspected.

"Serious consideration has already been given to this topic many times," said Eric Larson, MD, MPH, medical director for the Center for Health Studies at Group Health in Seattle.

Those opposed maintain that utilizing a dementia screening test in the general population would result in too many false positives. "Screening everybody is just going to lead to a lot of unnecessary workups and anxiety," Dr. Larson said.

There also are concerns that such screening could stigmatize individuals, particularly those who are unwilling or unable to get follow-up testing to confirm if they truly have dementia or are just having a bad day.

A study published in the Journal of General Internal Medicine in July 2005, for instance, found that just more than half of patients who tested positive during screening in a primary care setting would agree to a formal diagnostic assessment. The reasons why were unclear in this paper, although additional research by these authors suggests that many were afraid of losing their driver's licenses, being placed in nursing homes, having problems getting long-term care insurance or experiencing other forms of discrimination. These findings are expected to be published soon.

"We found a lot of stigma," said Malaz Boustani, MD, MPH, lead author and assistant professor of medicine at Indiana University School of Medicine in Indianapolis. "We have to make sure that the benefit of screening outweighs the harms."

Of those who were willing to confirm a diagnosis, 47% were diagnosed with dementia; 33% were cognitively impaired. About 20% were normal.

"Unfortunately, in the real world, many people stop at the screening level and never get evaluated," Dr. Boustani said. "They might have mild cognitive impairment. They might have normal function."

Physicians also report that, with the awareness of Alzheimer's and other dementias increasing, late diagnosis is the exception rather than the rule and that they can pick up cases without screening everyone. Family members often will mention if something is amiss. If the physician and patient have a standing relationship, problems usually will be noticed. Those who are most likely to be diagnosed at a late stage tend to be the least likely to see a doctor regularly.

"They live alone and, because of their dementia, they are basically isolated," said Alan Adelman, MD, vice chair for Academic Affairs and Research in the Dept. of Family and Community Medicine at Penn State University College of Medicine. "They're invisible to the system."

In addition, many believe that the arrangements patients should make after an Alzheimer's diagnosis, such as having a living will or creating advanced directives, are things that many patients in this age range should be doing anyway. Also, although a handful of Alzheimer's treatments have become available over the years, their effects tend to be modest.

Several studies have shown that drugs such as cholinesterase inhibitors slow the rate of cognitive decline but have little effect on function. Many believe that they are not beneficial enough to outweigh the downsides of screening.

"It's not like these are miracle drugs," Dr. Adelman said.