USPSTF: No to Routine Screening for Cognitive Impairment

March 26, 2014

There is insufficient evidence to recommend routine screening for cognitive decline in older adults in the primary care setting, according to a new review by the US Preventive Services Task Force (USPSTF).

The review, published in the Annals of Internal Medicine on March 25, is an update to the organization's previous overview in 2003, which found insufficient evidence to recommend for or against routine screening for dementia in older adults.

The current review looked at the evidence on screening for dementia and mild cognitive impairment in community-dwelling adults in the general primary care population who are older than age 65 years and have no signs or symptoms of cognitive impairment. Evidence on benefits, harms, and test performance of screening instruments and the benefits and harms of commonly used treatment and management options for older adults with mild cognitive impairment or early dementia was included.

The researchers concluded that the evidence on screening for cognitive impairment is lacking and that the balance of benefits and harms cannot be determined.

But in a statement in response to the USPSTF review, the Alzheimer's Association pointed out, "It is very important for people to understand that 'inadequate evidence of benefit' of screening is not the same thing as evidence of no benefit."

One of the authors of the USPSTF review, Douglas K. Owens, MD, Veterans Affairs Palo Alto Health Care System, Palo Alto, and Stanford University, California, commented to Medscape Medical News: "We couldn't recommend for or against routine screening. But it is important to make the distinction that we are talking about asymptomatic individuals. If a person has concerns about their memory, they should be definitely be evaluated appropriately."

Outcome Data Needed

He explained that there is enough information to say that the tests to evaluate cognitive impairment can be useful in helping people understand whether they need further evaluation. "But we don't have evidence that routine use of these tests in everyone at a certain age leads to better outcomes."

The USPSTF reviewers looked at drug therapy and nondrug therapy options for cognitive impairment and found more evidence on both than at the 2003 review, but not enough evidence that they lead to better health outcomes.

"For drug therapy, the benefits are modest and of uncertain clinical importance and the drugs have side effects," Dr. Owens said. "And while nondrug therapy such as cognitive training can be useful in some circumstances, again evidence of benefit on long-term outcomes is lacking.

"In order to recommend routine screening we would need better evidence that this would lead to better health outcomes," he added. "These studies have not been done broadly throughout the population. So we need more studies on the effect of screening and the effect of interventions."

He explained that if there was a treatment that provided a clear benefit, then that may alter the recommendations on screening. "But we would still need evidence that screening would produce better outcomes rather than just giving the treatment to patients when they develop symptoms."

He added that in the absence of a clearly beneficial treatment, screening studies would still provide useful data on how people use this information and what they do with it.

Regular Cognitive Evaluation

Elaborating on the views of the Alzheimer's Association, Maria Carrillo, PhD, vice president of medical and scientific relations, explained to Medscape Medical News that "inadequate evidence of benefit" means there is not enough evidence to make an informed recommendation one way or the other about screening for cognitive decline. More well-designed, long-term research is needed to generate the evidence.

"Therefore, no one should misconstrue this USPSTF guidance document to imply that there are no benefits to regular cognitive evaluations, or that regular evaluations are harmful," Dr. Carrillo said. "As is made apparent by the USPSTF guidance document, more research is needed to develop better and simpler diagnostic tools, verify the NIA [National Institute on Aging]/Alzheimer's Association new diagnostic criteria for Alzheimer's disease, and confirm what experts are already telling us — that early detection leads to better outcomes and reduced costs."

She noted that the Alzheimer's Association is not in favor of "1-time" screening — in which a brief test is conducted on 1 occasion — which it believes is associated with a high rate of false-positive and false-negative results.

Rather, it advocates cognitive evaluation and regular follow-up assessments in a medical setting to establish a baseline and track change over time, such as through the Medicare Annual Wellness Visit. "Routine cognitive assessments are not screening, but are a way to detect change over time that could indicate underlying pathology," Dr. Carrillo notes.

She points out that as many as 50% of people with Alzheimer's disease or another form of dementia do not receive a formal diagnosis. In addition, when a diagnosis is received, it is often after the dementia has progressed significantly. "An early diagnosis allows people with Alzheimer's disease or another dementia and their families a better chance of benefiting from available drug and nondrug therapies and more time to plan for the future."

The Alzheimer's Association also has developed a list of 10 Early Signs and Symptoms of Alzheimer's Disease. If individuals have experienced any of the warning signs, it's important to seek a comprehensive diagnostic evaluation from a physician who is experienced in diagnosing and treating Alzheimer's, Dr. Carrillo said.

Ann Intern Med. Published online March 25, 2014. Abstract


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