Which are best screening tools for predicting potential dementia and cognitive impairment?

USA: In a new Annals 'Beyond the Guideline feature, two experts review the available evidence about cognitive impairment to determine effective screening tools, interventions to improve patient outcomes, and the circumstances under which they would recommend screening for cognitive impairment (CI). All ‘Beyond the Guidelines’ features are based on the Department of Medicine Grand Rounds at Beth Israel Deaconess Medical Center (BIDMC) in Boston and include print, video, and educational components published in Annals of Internal Medicine. 

Dementia, according to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, is defined by a significant decline in 1 or more cognitive domains that interferes with a person’s independence in daily activities. Mild cognitive impairment differs from dementia in that the impairment is not sufficient to interfere with independence. A variety of screening tests are available for Cognitive Impairment. A positive screening test does not diagnose CI; rather it should lead to additional testing to confirm the diagnosis. Upon review of the evidence, the United States Preventive Services Task Force (USPSTF) concluded in 2020 that the evidence was insufficient to assess the balance of benefits and harms of screening for cognitive impairment in older adults (“I statement”). The USPSTF did clarify that although there is insufficient evidence, there may be important reasons to identify CI.

BIDMC Grand Rounds discussants, Michael Barry, M.D., Chair of the U.S. Preventive Services Task Force and a Professor of Medicine at Harvard Medical School, and Deborah Blacker, M.D., ScD, member of the Department of Psychiatry and the Alzheimer's Disease Research Center at Massachusetts General Hospital and Professor of Psychiatry at Harvard Medical School recently debated the case of Ms. B., a 75-year-old woman who, along with her primary care physician, were wondering whether she should be screened for memory loss given multiple risk factors and her desire to be proactive about her medical care.

Dr. Barry explained the rationale for the “I” statement and the lack of sufficient evidence from either the direct or indirect evidence pathway to recommend for or against screening. Dr. Blacker agrees that the available screening tests have issues with reliability, especially in certain patient populations. Both discussants also agree that the established agents have limited efficacy and have not been observed to change the course of the disease. Dr. Blacker reviewed that the newer anti-amyloid agents may change the course of the disease, but any cognitive benefits are modest and carry the risk of significant adverse effects.

Dr. Barry reviewed that although the USPSTF found that there is insufficient evidence to recommend for or against screening, there may be important reasons to identify CI, as early detection may allow for the identification and treatment of reversible causes, help clinicians be aware of patients who might have difficulty understanding and adhering to medical treatment plans, and provide useful information for patients and families as they begin advance care planning. Dr. Blacker concludes that these potential benefits add to the importance of developing a system that conducts and supports screening in primary care. In summary, Dr. Barry would leave the informed decision to screen our patient, Ms. B, to her and her clinician. Dr. Blacker would grant Ms. B's request for screening, as she thinks Ms B's request may reflect greater difficulties than are otherwise apparent and that, given her family responsibilities and complex medical regimen, the prompt recognition of CI is of particular importance.

Reference:

Risa B. Burns, Michael J. Barry, Deborah Blacker, and Zahir Kanjee, Would You Screen This Patient for Cognitive Impairment?, https://doi.org/10.7326/M23-1808.