Unclear Whether Older Adults Should Be Screened for Cognitive Impairment

By Will Boggs MD

February 26, 2020

NEW YORK (Reuters Health) - Currently there is insufficient evidence to determine whether screening for cognitive impairment in older adults is safe and beneficial, according to an updated recommendation statement from the U.S. Preventive Services Task Force (USPSTF).

"There is currently very little evidence that supports or refutes that systematically screening all older adults without recognized signs or symptoms of cognitive impairment results in beneficial outcomes or causes harm," Dr. Carrie D. Patnode from Kaiser Permanente Evidence-based Practice Center, Kaiser Permanente Northwest, Portland, Oregon told Reuters Health by email. "We need more research to inform this important question."

Dr. Patnode and colleagues systematically reviewed the accuracy of cognitive screening instruments and benefits and harms of interventions to treat cognitive impairment in adults aged 65 years and older in order to inform the USPSTF's updated recommendation statement.

"While our review identified more than 260 studies that addressed how well screening tests can detect cognitive impairment in primary care and how effective interventions are in managing cognitive impairment, there is a glaring lack of evidence on whether screening older adults without recognized signs or symptoms of cognitive impairment improves outcomes for those patients or their families or whether it affects clinical decision making," she said.

"Additionally, while a number of nonpharmacologic and pharmacologic treatments are available to improve or slow cognitive and functional decline among persons with dementia, the benefits of these interventions appear quite small and of uncertain clinical importance."

The only study that examined the direct effect of screening for cognitive impairment found no significant differences in health-related quality of life at 12 months, compared with not screening.

While the Mini-Mental State Examination (MMSE), the most commonly used instrument, showed 89% sensitivity for detecting dementia in 15 studies, medications approved to treat Alzheimer dementia provided only minor improvements in cognition over three months to three years.

Psychoeducation interventions for caregivers provided only small relief of caregiver burden over three to 12 months.

Limited data on the potential harms of screening revealed significantly higher adverse event rates for acetylcholinesterase inhibitors, and individual studies revealed increased rates of bradycardia, syncope, falls, and the need for pacemaker placement among those exposed to such medications. Other pharmacologic and nonpharmacologic interventions were not apparently associated with significant harms.

Based on this evidence, USPSTF concludes "that the current evidence is insufficient to assess the balance of benefits and harms of screening for cognitive impairment in older adults."

Despite this recommendation, USPSTF advises clinicians to remain alert to early signs and symptoms of cognitive impairment (such as problems with memory or language) and evaluate them as appropriate.

Dr. Chyke Doubeni, USPSTF member from Mayo Clinic, Rochester, Minnesota, told Reuters Health by email, "Cognitive impairment is a serious concern for many older adults, their families, and their clinicians, and they want to know more about how primary care clinicians can help. We were encouraged to see some new research since the last time we reviewed this topic, although it wasn't enough for us to make a clear recommendation."

"While we can't say exactly why there is a lack of evidence in this area, we are continuing to call for more research that can inform evidence-based recommendations and decision-making," he said.

Dr. Ronald C. Petersen from Mayo Clinic Rochester, Rochester, Minnesota, who co-authored an editorial related to these reports, told Reuters Health by email, "I would not discourage physicians from evaluating cognitive function in their patients. While the data from Class I studies may not be there, that does not mean that there is no benefit to the patients, families, or the physicians themselves from cognitive assessments."

"While difficult to conduct, we need longitudinal studies on the value of cognitive screening in diverse populations over many years," he said. "I think it is risky to conclude anything about the utility of screening when the participants are followed for only 12-24 months. The true value may not reveal itself for years. Expensive, challenging and difficult, but these studies are needed."

Dr. Howard Fillit, Chief Science Officer and Founding Executive, Alzheimer's Drug Discovery Foundation, New York, told Reuters Health by email, "The recommendation, like all recommendations from the Task Force, reflects a public health, not an individual patient perspective. As a geriatrician who has treated thousands of patients with dementia, I can tell you that there is no doubt that if a patient has a memory complaint, or if a loved one or other related person reports a memory complaint, then a cognitive assessment should be completed."

"Individual patients with the 'warning signs' of cognitive impairment and dementia should be properly assessed, diagnosed, treated, and managed," he said. "Like with other chronic diseases, early diagnosis is important to quality of care provided by physicians."

Dr. Michael H. Rosenblum from Health Partners Center for Memory and Aging, St. Paul, Minnesota told Reuters Health by email, "This report does not refute or support cognitive screening in the asymptomatic elderly population. However, the Medicare Annual Wellness visit requires an objective assessment of cognitive, and likewise, this report does not provide an argument to no longer continue screening in this setting."

"I receive frequently referrals from primary care who perform cognitive screening during the Medicare Annual Wellness visit," he said. "Most of the time, there is an underlying cognitive disorder that is (diagnosed) after these individuals undergo a more formal cognitive evaluation. Had these patients never undergone cognitive screening, their diagnosis of mild cognitive impairment or dementia would never have been made."

Dr. Angela Sanford from St. Louis University School of Medicine in Missouri, who has researched various aspects of cognitive impairment, told Reuters Health by email, "In clinical practice, the benefits of screening for mild cognitive impairment and dementia are clear. For one, safety issues, such as driving and independent living, can be discussed prior to a crises occurring. Second, there are often reversible causes, such as polypharmacy, depression, and obstructive sleep apnea, that when treated, will result in the person thinking much (more clearly). Third, when cognitive issues are caught earlier, as often occurs with screening, the individual can participate in shared decision making and voice their care preferences."

"While the evidence-based research on cognitive screening is lacking, most geriatricians and clinicians who care for older adults are proponents of regular screening rather than case-finding because the benefits far outweigh the harms," she said.

The full recommendation statement, along with the evidence report supporting it, appears in JAMA.

SOURCE: http://bit.ly/32sNRJR, http://bit.ly/2SYE8rx and http://bit.ly/37WiXKP JAMA, online February 25, 2020.