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Dementia Screening: Evidence Is Lacking, Says USPSTF

Not enough evidence for benefit that exceeds potential harms exists to recommend screening older adults who don’t have signs of cognitive impairment, the U.S. Preventive Services Task Force (USPSTF) said Tuesday.

In its final statement on the subject, the USPSTF concluded that “the current evidence is insufficient to assess the balance of benefits and harms of screening for cognitive impairment in older adults,” wrote task force chair Douglas Owens, MD, of Stanford University in California, and colleagues in JAMA.

“The task force is calling for more research to address this serious issue,” Owens said in a statement. “Research is especially needed on whether screening and early detection of cognitive impairment helps patients, caregivers, and doctors make decisions about healthcare or plan for the future.”

The recommendations apply to community-dwelling adults, ages 65 or older, without signs of cognitive impairment, and update similar guidelines that were published in 2014. A draft version of the new recommendations were available for public comment in fall 2019.

In an accompanying evidence report, Carrie Patnode, PhD, MPH, of Kaiser Permanente in Portland, Oregon, and colleagues, looked at cognitive screening utility, cognitive testing accuracy, harms of screening, interventions for people with cognitive interventions, and harms of those interventions.

In some areas, like testing accuracy, evidence was clear: “Screening instruments can adequately detect cognitive impairment,” Patnode and colleagues wrote.

But in other areas, “the studies aren’t out there that address the questions,” said Ronald Petersen, PhD, MD, of the Mayo Clinic in Rochester, Minnesota, in an interview with MedPage Today.

Only one trial focused on the utility of screening in primary care and it failed to demonstrate benefit or harm, noted Petersen and Kristine Yaffe, MD, of the University of California San Francisco, in an accompanying editorial.

That study — the IU CHOICE trial — was designed and funded to address the lack of empirical data in the previous USPSTF review.

IU CHOICE faced “many, many challenges” including recruitment and retention problems, said Petersen, who wasn’t involved with the trial. Of 134 people who screened positive for dementia, only 46 people (34%) received subsequent evaluation. “The study was underpowered,” Petersen said. “I think it speaks to the fact that studies like this are very difficult to do.”

The 12-month follow-up period in IU CHOICE also may have been too short, Petersen and Yaffe noted. “When you’re assessing cognitively unimpaired people, you really need to follow these people for years,” Petersen said. “The outcome is going to be down the road somewhere.”

In their review of interventions, Patnode and colleagues looked at 224 randomized trials and three observational studies, and concluded that FDA-approved treatments like acetylcholine esterase inhibitors and memantine had common, known adverse effects and showed short-term benefits only.

Overall, Patnode’s group found no empirical evidence that screening for cognitive impairment improves patient or caregiver outcomes or causes harm. “It remains unclear whether interventions for patients or caregivers provide clinically important benefits for older adults with earlier detected cognitive impairment or their caregivers,” they wrote.

Potential harms in diagnosing dementia should “include uncertainty about the meaning of a diagnosis and the inability to accurately advise patients about prognosis,” observed Carol Brayne, MD, of University of Cambridge in England, in an editorial in JAMA Internal Medicine.

In the U.K., older adults with unplanned hospital admissions have been screened for dementia, a policy withdrawn because its benefit was unclear, Brayne noted.

“Risk reduction for cognitive impairment includes stopping smoking and moderating alcohol intake; promoting healthful diet and physical activity; and preventing and managing hypertension, cardiovascular disorders, diabetes, and depression,” she wrote. “Clinicians can recommend these approaches to reduce risk to all older adults without the need for any cognitive screening.”

It’s important that physicians, patients, and families understand that the USPSTF recommendation “does not imply that people with memory or related cognitive problems should not be assessed,” said Howard Fillit, MD, executive director and chief science officer at the Alzheimer’s Drug Discovery Foundation in New York, who was not part of the task force. “In fact, about 10% of people with cognitive impairment have a reversible cause.”

“The question, from a population health societal perspective, is not whether or not there should be screening, but what population should be screened,” Fillit told MedPage Today. “Certainly people with complaints of memory impairment should be screened and assessed, especially individuals 75 and over, in whom cognitive impairment is highly prevalent.”

Primary care physicians have limited time with patients during office visits and this report might give them a reason to not include cognitive screening in their assessment, Petersen and Yaffe pointed out. “It would be a mistake if clinicians did not consider the value of screening for cognitive impairment on a case-by-case basis,” they wrote.

The American Academy of Neurology (AAN) recommends that neurologists and other physicians providing neurological care should screen patients age 65 and older yearly for cognitive impairment and issued new metrics in September 2019 to improve patient care in this area.

Last Updated February 25, 2020


The research was funded by the Agency for Healthcare Research and Quality (AHRQ) to support the USPSTF. All USPSTF members disclosed receiving travel reimbursement and an honorarium for participating in USPSTF meetings. One task force member disclosed support from Healthwise.

Petersen disclosed relevant relationships with Roche, Merck, Biogen, Eisai, Genentech, GE Healthcare, the GHR Foundation, and the Mayo Clinic Foundation for Medical Education and Research. Yaffe disclosed relevant relationships with Alector, Eli Lilly, the Beeson Scholars Program, the Global Council of Brain Health, the Doris Duke Charitable Fund, and the Alzheimer’s Disease Drug Discovery Fund.

Brayne disclosed no relevant relationships with industry.