The Mini-Cog has been found to be highly accurate. And, unlike the MMSE, the Mini-Cog is not skewed by education level or language skill. One study based on interviews with “informants”—the family, friends, or caregivers of patients being tested for dementia—examined the Mini-Cog’s ability to differentiate between 129 demented and 120 nondemented older adults who were culturally, linguistically, and educationally heterogeneous. The Mini-Cog classified 96% of participants correctly and had a sensitivity of 99%.24
Another retrospective analysis of a random sample of more than 1100 elderly people compared the Mini-Cog to the MMSE. In this case, the Mini-Cog and MMSE (with a cut point of 25) demonstrated similar sensitivity (76% vs 79%) and specificity (89% vs 88%) for identifying individuals with dementia.25
Jack S, whose daughter worried about his “forgetfulness,” was given the Mini-Cog. He drew a clock with the big hand incorrectly placed, and recalled only 2 words. Because his daughter was with him, the physician asked her to complete a Functional Activities Questionnaire (FAQ), a test designed for family members, caregivers, and other informants. The findings indicated that Jack had dementia, and the physician gave the family a referral to a specialist in elder care.
The Mini-Cog–FAQ. A recent study paired the Mini-Cog with the FAQ, which asks the informant to rate the patient’s ability to perform a variety of activities—eg, paying bills, shopping, engaging in hobbies, and preparing a meal. When used alone, the FAQ has a high sensitivity and specificity, but patient testing is still necessary. Used together, the Mini-Cog–FAQ allowed researchers to classify patients as cognitively normal, demented, or mildly cognitively impaired with 83% accuracy.26
Montreal Cognitive Assessment detects mild impairment
The MoCA is a 10-minute screening tool designed to help physicians detect mild cognitive impairment, which is considered to be predictive of dementia.27 This tool is especially useful for individuals who present with memory complaints but achieve a normal score (26-30) on the MMSE, as the MoCA is a better measure of executive function. It tests visuospatial skills, for example, by asking patients to draw lines connecting letters and numbers in a numerical/alphabetical sequence. It also requires abstract reasoning, by asking patients to explain the similarity between, say, a banana and an orange or a train and a bicycle.
Indicators point to ischemic disease. Janet M, the patient who had an episode of acute confusion at the mall, was an ideal candidate for the MoCA. But her physician was more familiar with the MMSE and screened her with that tool first. She received a perfect score on the MMSE, but continued to worry that the episode at the mall was the beginning of dementia, so her physician followed up with the MoCA. Only after receiving a 28 of a possible 30 on the MoCA (≥26 is considered normal) was Janet reassured that she was not suffering from dementia. Based on evidence of poorly controlled blood pressure (167/89 mm Hg), the physician determined that the brief episode was more consistent with a transient ischemic attack. The patient was referred for brain imaging to be evaluated for ischemic disease.
Like the MMSE, the MoCA has been widely translated. It is available online in more than 20 languages.
Interpreting the MoCA. In a validation study of patients from a community clinic and an academic center, the test was administered to 94 patients with mild cognitive impairment, 93 patients with mild AD (MMSE score ≥17), and 90 healthy elderly adults.27 At a cut point of 26, the MMSE demonstrated a sensitivity of 18% in detecting mild impairment; among patients with mild AD, its sensitivity was 78%. In contrast, the MoCA detected 90% of cases of mild impairment and had 100% sensitivity for mild AD. Specificity was excellent for both the MMSE and the MoCA (100% and 87%, respectively). Thus, physicians can reassure patients who achieve high scores on the MoCA that there is no indication of cognitive impairment, and schedule follow-up testing in a year. Those whose MoCA scores indicate some impairment can be referred to memory clinics or consultants for a more thorough work-up.
The AD 8 Dementia Screening Interview detects early changes
This brief screening tool—a simple 8-question interview—takes about 3 minutes to administer, and accurately identifies patients in the earliest stages of AD or another dementing disorder.28 The questions examine the domains of memory, orientation, judgment, and function.
The test, which is designed primarily for an informant but is sometimes given to patients themselves, can be administered in a variety of ways: by reading the questions to the respondent, either in person or by telephone, or on a clipboard for self-administration. The AD 8 simply asks whether specific changes have been noted, without attributing causality. The respondent answers Yes, No, or Don’t Know. The final score is a sum of the number of Yes answers. A score of ≥2 is suggestive of cognitive impairment. The AD 8 has a sensitivity of 84% and specificity of 80%.28