USPSTF: Evidence insufficient for routine dementia screening
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HealthDay News -- There is insufficient evidence to assess the benefit versus harm of routine cognitive impairment screening in older adults without signs and symptoms of mild cognitive impairment (MCI) or dementia, according to draft recommendations from the U.S. Preventive Services Task Force (USPSTF).
"Although the benefits and harms of what we can offer patients through routine screening are unclear right now, clinicians should remain alert to early signs or symptoms of cognitive impairment and evaluate their patients as appropriate," Task Force co-vice chair Albert Siu, MD, MSPH, said in a statement.
The draft recommendations are an update to the USPSTF's previous 2003 statement on the topic and consisted of a literature review that included 16,179 abstracts and 1,190 articles published since 2001. USPSTF aimed to answer five key questions:
- Does screening for cognitive impairment in community-dwelling older adults in primary care–relevant settings improve decision-making, patient, family or caregiver, or societal outcomes?
- What is the test performance of screening instruments to detect cognitive impairment in elderly, community-dwelling primary care patients?
- What are the harms of screening for cognitive impairment?
- Do interventions for MCI or mild to moderate dementia in older adults improve decision-making, patient, family or caregiver, or societal outcomes?
- What are the harms of interventions for cognitive impairment?
In terms of early detection and intervention, evidence was inadequate to determine screening benefits, the Task Force concluded. No studies were identified that addressed questions one and three.
However, the USPSTF was able to determine that there is now adequate information on the accuracy of some screening tools, a change from the 2003 recommendation statement. Additionally, the Task Force came up with four suggestions for practice regarding potential preventable burden, the potential harms of interventions for cognitive impairment, costs and current practice.
In terms of potential preventable burden, early recognition of cognitive impairment can help patients make diagnostic and treatment decisions, and enables clinicians to anticipate problems patients may have in understanding and adhering to recommended therapy. Therefore, the Task Force recommends clinicians remain alert to early signs or symptoms of cognitive impairment and evaluate patients as appropriate, despite insufficient evidence to recommend routine screening.
In regard to cognitive impairment interventions, the only FDA-approved pharmacologic treatments are acetylcholinesterase inhibitors (AChEIs) and memantine. USPSTF cautions that AChEIs are associated with adverse events, including gastrointestinal symptoms, serious central nervous system disturbances and brachycardia. Despite limited evidence on nonpharmacologic interventions, there are no known serious adverse events associated with exercise therapies.
The cost of cognitive impairment screening as well as test sensitivity and specificity varies widely, USPSTF determined. The most widely studied screening instrument, the Mini-Mental State Examination (MMSE), takes approximately 10 minutes to administer and is not free.
"Although optimal sensitivity and specificity of the MMSE likely vary depending on the patient's age and education level, a large body of literature suggests a general cut-point of 23/24 or 24/25 is appropriate for most primary care populations," the Task Force wrote.
In current practice, dementia diagnosis and treatment is based most often on patient symptoms and caregiver concerns, but as many as 29% to 75% of patients with signs of cognitive impairment go undiagnosed.
"The use of a brief structured assessment (such as the General Practitioner Assessment of Cognition, Mini-Cog, Memory Impairment Screen, AD8, or short version of the Informant Questionnaire on Cognitive Decline in the Elderly) is recommended if signs or symptoms of cognitive impairment are present or if an informant is not available to confirm the absence of signs or symptoms," USPSTF wrote.