Identifying cognitive impairment during the Annual Wellness Visit: Who can you trust?

While informants possessed some knowledge about a patient’s cognitive status and were able to supply helpful anecdotal information, their ratings correlated only modestly with objectively measured cognition. This is not surprising given the volume of research demonstrating rater and observer bias.

Rely instead on an objective cognitive screening test. Of greatest relevance, these results indicate that an objective cognitive screening test is more accurate in identifying and measuring cognitive impairment than is the rating of a patient or an informant. Both the MOST and MMSE outperformed patients and informants in assessing patients’ severity of cognitive impairment, including those with milder problems. This last finding is particularly important given that less impaired patients are more likely to visit their doctor without an informant and to appear relatively intact when interviewed or observed by the physician.¹⁷ Without an objective test, their cognitive impairment would likely be missed.³²

The MOST outperformed the MMSE in detecting dementia and determining disease severity on a sample of 700 patients, and demonstrated twice the sensitivity for disease detection in those who were mildly impaired.²⁶ The current study confirms that the MOST has a significantly higher correlation with dementia severity than does the MMSE, and significantly higher correlations with longer standardized memory tests.

MOST, MMSE test-taking time varies, too. Time constraints are an important consideration in a medical office. The average time to administer the MOST on cognitively impaired patients (a group that is slower to perform than patients with normal cognition) is 4.5 minutes.²⁶ The MMSE, by comparison, takes 10 minutes or more.^33,34

Cognition is as measurable as body mass index, blood pressure, height, weight, and level of depression, also mandated in the Annual Wellness Visit. Numbers are easily recorded and compared, while impressions or even a positive (>2) AD8 score are less precise. Provider observation, even if informed by family report, is not as sound a basis for risk analysis, treatment planning, or future monitoring as is an objective measure. Because several current screening tests for dementia possess known reliabilities over time,^26,33,35 the physician can periodically repeat such a test to assess treatment response and ongoing risk.

Is there a place for a subjective rating scale? Possibly. A waiting room tool such as the VACS, combined with an objective test, may alert the clinician to a patient with anosognosia. These patients require different management strategies if treatment is to be effective. The care team faces an even greater challenge if an informant shares the patient’s lack of awareness. Conversely, a favorable cognitive screening result and a high score from the informant would give all parties assurance that cognition was normal.

Study limitations. The primary limitation of this study is that it was conducted in a tertiary memory center, where most patients have either suspected or demonstrated cognitive deficits. The relative proportion of normal to impaired patients is, consequently, different from that found in the primary care office, in which about 15% would have mild cognitive impairment³⁶ and a similar percentage would have dementia.³⁷ A replication of this study in such an environment would be helpful. On the other hand, without a companion neuropsychological evaluation as a criterion, the accuracy of self- or informant-report is more difficult to measure. As noted above, 20% of elders volunteering for a study on “normal cognitive functioning” showed significant objective deficits.³¹

Assessment of cognitive impairment in the primary care physician’s office is uniquely challenging. Physicians are taught to respond to the complaints of patients. But when a patient has dementia, that approach does not work. Family reports are helpful, but not sufficiently accurate. The recent Alzheimer’s Association report³⁷ notes that “Medicare’s new Annual Wellness Visit includes assessment for possible cognitive impairment,” but also points out that “many existing barriers affect the ability or willingness of individuals and their caregivers to recognize cognitive impairment and to discuss it with their physician.” We agree, and we believe that a sound approach to this problem would be for primary care physicians to consistently use an objective tool to measure cognitive functioning in the Annual Wellness Visit and in follow-up visits. A score that reflects the current level of cognition, provides diagnostic information, and reflects change in cognitive status over time will optimize this unique opportunity for earlier detection and potentially earlier treatment of dementia.