Informant-based Dementia Screening in a Population-based Sample of African Americans

Department of Neurology & Psychiatry, School of Medicine, St Louis University, 1438 South Grand Boulevard, St Louis, MO 63104, USA.
Alzheimer disease and associated disorders (Impact Factor: 2.44). 04/2009; 23(2):117-23. DOI: 10.1097/WAD.0b013e318190a709
Source: PubMed


An informant-based screening tool for dementia may be useful in population-based studies of minority populations.
Investigate the feasibility of screening for very mild dementia in a community sample of African Americans using an informant-based screening tool (AD8).
Cohort study.
One hundred forty-seven persons from the African American Health (AAH) project were screened for dementia; 61 of 93 who were invited had follow-up clinical assessments for dementia diagnosis.
The AD8, Mini-Mental State Examination, Short Blessed Test, Brief Instrument for Dementia Detection, and a neuropsychologic battery were administered at visit 1. The Clinical Dementia Rating (CDR) was administered at visit 2 by clinicians blinded to visit 1 results; the presence of dementia was determined by a CDR greater than 0.
Four hundred sixty-five individuals from the AAH cohort were sent a letter describing the study and, among this group, 252 individuals were contacted by phone to request participation in this study. Six percent (14/252) of the participants contacted by phone were unable to identify an informant (required for the AD8). One hundred fifty individuals agreed by phone to participate of which 2% (n=3) did not have an informant available at the time of participation. The AD8 alone was effective at discriminating between CDR 0 and CDR 0.5 (area under the curve=0.847; P<0.001; 95% confidence interval, 0.73-0.96).
A brief informant-based instrument, the AD8, has high sensitivity and specificity for distinguishing CDR 0 from CDR 0.5 in the community. Informant availability may not be a barrier for using the AD8 in an African American community sample; however, further study in larger samples with a higher response rate, different community settings (eg, community clinics), and among older age groups (eg, age 75+) is warranted to confirm this.

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    • "The administration of the AD8 requires minimal training and can be conducted either in person or over the phone within 3 minutes [13] [14] [15] [16] [17] [18]. The AD8 has been previously validated to identify patients with varying severity of cognitive impairment in epidemiology studies [13] [14] [17] [19] and tertiary clinical settings [15] [16] [18] [20]. It is also well tolerated by the informants and healthcare professionals in primary healthcare settings [21]. "
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    ABSTRACT: The informant AD8 has excellent discriminant ability for dementia case finding in tertiary healthcare settings. However, its clinical utility for dementia case finding at the forefront of dementia management, primary healthcare, is unknown. Therefore, we recruited participants from two primary healthcare centers in Singapore and measured their performance on the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Clinical Dementia Rating (CDR), and a local formal neuropsychological battery, in addition to the AD8. Logistic regression was conducted to examine the associations between demographic factors and dementia. Area under the receiver operating characteristics (ROC) curve analysis was used to establish the optimal cut-off points for dementia case finding. Of the 309 participants recruited, 243 (78.7%) had CDR = 0, 22 (7.1%) CDR = 0.5, and 44 (14.2%) CDR ≥1. Age was strongly associated with dementia, and the optimal age for dementia case finding in primary healthcare settings was ≥75 years. In this age group, the AD8 has excellent dementia case finding capability and was superior to the MMSE and equivalent to the MoCA [AD8 AUC (95% CI): 0.95 (0.91-0.99), cut-off: ≥3, sensitivity: 0.90, specificity: 0.88, PPV: 0.79 and NPV: 0.94; MMSE AUC (95% CI): 0.87 (0.79-0.94), p = 0.04; MoCA AUC (95% CI): 0.88 (0.82-0.95), p = 0.06]. In conclusion, the AD8 is well suited for dementia case finding in primary healthcare settings.
    Journal of Alzheimer's disease: JAD 10/2015; 49(1). DOI:10.3233/JAD-150390 · 4.15 Impact Factor
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    • "The AD8 uses informant information; the absence of an observant informant may limit use in certain clinical situations. However, informant interviews can be successfully applied in populations with lower educational attainment (Galvin et al., 2007a; Espinosa et al., 2008; Malmstrom et al., 2009). Additionally, the AD8 can be used as a patient interview in the absence of an informant (Galvin et al., 2007a) and can be administered in person or by phone (Galvin et al., 2006). "
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    ABSTRACT: Screening tests for Alzheimer's disease lack sensitivity and specificity. We developed the AD8, a brief dementia screening interview validated against clinical and cognitive evaluations, as an improvement over current screening methods. Because insufficient follow-up has occurred to validate the AD8 against the neuropathologic findings of Alzheimer's disease, we investigated whether AD8 scores correspond to impairment in episodic memory testing and changes in biomarkers of Alzheimer's disease (cerebrospinal fluid and amyloid imaging with Pittsburgh compound B) characteristic of symptomatic Alzheimer's disease. We also compared informant-based assessments with brief performance-based dementia screening measurements such as the Mini Mental State Exam. The sample (n = 257) had a mean age of 75.4 years with 15.1 years of education; 88.7% were Caucasian and 45.5% were male. The sample was divided into two groups based on their AD8 scores: those with a negative dementia screening test (AD8 score 0 or 1, n = 137) and those with a positive dementia screening test (AD8 score ≥2, n = 120). Individuals with positive AD8 scores had abnormal Pittsburgh compound B binding (P < 0.001) and cerebrospinal fluid biomarkers (P < 0.001) compared with individuals with negative AD8 scores. Individuals with positive AD8 tests and positive biomarkers scored in the impaired range on the Wechsler Logical Memory Story A (mean score 7.0 ± 4.5 for Pittsburgh compound B; mean score 7.6 ± 5.3 for cerebrospinal fluid amyloid beta protein 1-42). The AD8 area under the curve for Pittsburgh compound B was 0.737 (95% confidence interval: 0.64-0.83) and for cerebrospinal fluid amyloid beta protein 1-42 was 0.685 (95% confidence interval: 0.60-0.77) suggesting good discrimination. The AD8 had superior sensitivity in detecting early stages of dementia compared with the Mini Mental State Examination. The AD8 had a likelihood ratio of a positive test of 5.8 (95% confidence interval: 5.4-6.3) and likelihood ratio of a negative test of 0.04 (95% confidence interval: 0.03-0.06), increasing the pre-test probability of an individual having symptomatic Alzheimer's disease. Individuals with AD8 scores of ≥2 had a biomarker phenotype consistent with Alzheimer's disease and lower performance on episodic memory tests, supporting a diagnosis of Alzheimer's disease. Informant-based assessments may be superior to performance-based screening measures such as the Mini Mental State Examination in corresponding to underlying Alzheimer's disease pathology, particularly at the earliest stages of decline. The use of a brief test such as the AD8 may improve strategies for detecting dementia in community settings where biomarkers may not be readily available, and may enrich clinical trial recruitment by increasing the likelihood that participants have underlying biomarker abnormalities.
    Brain 11/2010; 133(11):3290-300. DOI:10.1093/brain/awq204 · 9.20 Impact Factor
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    ABSTRACT: Clinical neuropsychology is "an applied science that examines the impact of both normal and abnormal brain functioning on a broad range of cognitive, emotional, and behavioral functions." This chapter reviews the utility and limitations of the neuropsychological assessment of dementia in older adults, and sheds lights on the value of neuropsychological measures in research on cognitive aging and epidemiological studies of health among older adults. Neuropsychologists who work with older adults are most typically charged with the task of determining whether a pattern of test performance is indicative of a neurodegenerative disease. Several unique challenges emerge for the neuropsychologist in the context of aging, with one of the biggest challenges being the determination of whether a diagnosis is warranted at all. With advancing age comes unavoidable abatement of most biological systems. Continued research examining neuropsychological performance across autopsy-confirmed dementia groups will greatly facilitate the ability to draw diagnostic inferences from neuropsychological tests, and to identify those tests that are most useful in differential diagnosis.
    Handbook of the Psychology of Aging, 01/2011: pages 339-352; , ISBN: 9780123808820
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