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Introduction: With 36 million older adult U.S. drivers, safety is a critical concern, particularly among those with dementia. It is unclear at what stage of Alzheimer's disease (AD) older adults stop driving and whether preclinical AD affects driving cessation., Methods: Time to driving cessation was examined based on Clinical Dementia Rating (CDR) and AD cerebrospinal fluid biomarkers. 1795 older adults followed up to 24 years received CDR ratings. A subset (591) had cerebrospinal fluid biomarker measurements and was followed up to 17 years. Differences in CDR and biomarker groups as predictors of time to driving cessation were analyzed using Kaplan-Meier curves and Cox proportional models., Results: Higher CDR scores and more abnormal biomarker measurements predicted a shorter time to driving cessation., Discussion: Higher levels of AD biomarkers, including among individuals with preclinical AD, lead to earlier driving cessation. Negative functional outcomes of preclinical AD show a nonbenign phase of the disease., (Copyright © 2017 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)

Dementia is a common and under-diagnosed problem among the elderly. An accurate screening test would greatly aid the ability of physicians to evaluate dementia and memory problems in clinical practice. We sought to determine whether simple and brief psychometric tests perform similarly to the Mini-Mental State Examination (MMSE) in screening for dementia. Using a retrospective analysis, a series of standard, brief, psychometric tests were compared with each other and to the MMSE as screening tests for very mild dementia, using DSM-III-R criterion as the gold standard. Two independent cohorts from the Baltimore Longitudinal Study of Aging and the Washington University Alzheimer's Disease Research Center were evaluated. We found that two brief and simple-to-administer tests appear to offer similar degrees of sensitivity and specificity to the MMSE. These are the recall of a five-item name and address, "John Brown 42 Market Street Chicago" and the one-minute verbal fluency for animals. Combining these two tests further improves sensitivity and specificity, surpassing the MMSE, to detect dementia in individuals with memory complaints.

Objectives: To examine the reporting accuracy of collateral sources (knowledgeable informants) regarding very mild and mild dementia of the Alzheimer type (DAT) and to identify characteristics associated with collateral source accuracy., Design: Secondary data analysis of initial visits of individuals enrolled in a longitudinal study of healthy aging and Alzheimer disease., Setting: Urban Alzheimer disease research center., Participants: Pairs of 515 individuals with very mild (n = 203) or mild (n = 312) DAT and their collateral sources., Measurements: Collateral sources were asked separately during a semistructured interview by experienced clinicians to report current ability of the individual with DAT in memory, orientation, and judgment and problem solving. The clinical performance of the individuals with DAT in these domains was compared with these predictions., Results: Collateral sources were consistently and significantly accurate in reporting the cognitive capabilities of individuals with very mild and mild DAT. Although all types of collateral sources performed significantly better than chance, individual variables that correlated with collateral source accuracy included spousal relationship; living with the individual with DAT; frequent exposure to the individual; and age, education level, sex and dementia severity of the individual with DAT., Conclusion: Collateral sources are accurate in reporting the cognitive capabilities of individuals with DAT, even in the very mild stage of dementia.

Objective: To examine the earliest cognitive changes associated with the onset of dementia as well as changes associated with normal aging., Design: Longitudinal evaluation of participants with annual clinical and psychometric examinations for up to 15 1/2 years., Setting and Participants: Elderly volunteers (n = 82) enrolled with a Clinical Dementia Rating of 0 (cognitively intact) in longitudinal studies., Interventions: None., Main Outcome Measures: Clinical Dementia Rating and results of a 1 1/2-hour psychometric battery., Results: As estimated with survival analysis, 40% of participants had a Clinical Dementia Rating greater than 0 (cognitive decline) within 12 years of enrollment; 59% of these were judged to have dementia of the Alzheimer type or incipient dementia. Participants with poorer performance on psychometric testing at enrollment were at higher risk for cognitive decline subsequently. The rate of change in psychometric performance before clinically detectable cognitive change occurred was not significantly different between those who eventually developed dementia and those who remained stable, except for performance on the Logical Memory subtest of the Wechsler Memory Scale. When subtle cognitive decline was clinically detected, however, an abrupt deterioration in performance on independently administered psychometric tests was observed., Conclusions: Cognitively healthy elderly people maintain stable cognitive performance when measured longitudinally by both careful clinical evaluation and repeated psychometric testing. This stability is maintained unless and until they develop a dementing illness, at which time a sharp decline in performance is observed.

Objective: The influence of age on performance on clinical and psychometric assessments is examined in groups of nondemented persons and individuals with either very mild or mild dementia of the Alzheimer type (DAT)., Design: Initial clinical and psychometric assessments of persons enrolled in longitudinal studies of DAT and nondemented control subjects., Setting: Alzheimer's Disease Research Center at Washington University, St Louis, Mo., Participants: Volunteer samples of 108 people (44 men, 64 women) with mild DAT, 61 people (30 men, 31 women) with very mild DAT, and 122 healthy nondemented people (45 men, 77 women) were recruited between 1979 and 1991. Age ranged from 54 to 87 years. Persons with confounding medical, neurologic, or psychiatric disorders were excluded. Dementia severity was staged using the Clinical Dementia Rating scale., Main Outcome Measures: Five brief quantitative clinical tests included in the 90-minute clinician administered protocol, as well as 14 tests included in a 2-hour psychometric test battery., Results: Dementia severity affected performance on all measurements. Age did not influence performance on clinical assessments. There was a significant interaction between age and dementia severity on 10 of 14 psychometric measures. In general, older nondemented individuals performed less well than younger nondemented individuals while older mildly demented persons performed about the same as, or slightly better than, their younger counterparts., Conclusions: Age does not affect performance on brief clinical assessment instruments. However, age affects psychometric performance differently in cognitively intact persons when compared with persons with DAT. As a result, psychometric differentiation between cognitively normal and demented individuals is more difficult in older populations.