Persons with CIND were more likely to have a negative outcome than persons with NCI during a 5-year interval. This was true across etiologic subcategories and suggests that the use of specific diagnostic criteria sets does not improve our identification of those who develop dementia compared with a broader, more inclusive approach. More factors contributed to the prediction of all forms of dementia than to AD, but the most accurate prediction was for those who remained dementia free.

Well-researched statistical methods are required to guide clinicians in determining the significance of test score changes in serial neuropsychological assessment of older adults. The following six change score methods were examined using five-year test-retest data from the Canadian Study of Health and Aging: the standard deviation method, three reliable change indices (RCIs), and two standardized regression-based methods. Changes in scores on four memory measures were examined in cognitively healthy older adults, and the RCI with a correction for practice/aging effects most accurately classified this normal variability. Diagnostic change (i.e., developing dementia versus remaining cognitive healthy) was also examined in relation to memory test score changes. All change score methods were significantly associated with diagnostic change, though the strength of association varied by measure and method. In contrast to some previous research, RCIs were found to be useful when making diagnostic discriminations in older adults.

Identification of persons at risk for developing dementia is of increasing importance as the proportion of persons over the age of 65 years grows globally. This review examines the neuropsychological literature specifically addressing the concept of impaired cognitive functioning of insufficient magnitude to warrant a diagnosis of dementia and its meaning with respect to the development of dementia. Although the most obvious finding in the literature is that persons with impaired cognitive functioning have varied outcomes, it is clear that a significant proportion of persons with mild cognitive impairment progress to dementia over a 1- to 2-year interval and approximately 50% progress to dementia by 5 years. The best and most commonly identified predictors of decline to dementia include age and lower baseline performance on neuropsychological measures (e.g., measures of memory). In discussing these findings, issues related to sample definition, sample selection, and methodology are identified and recommendations for future research are provided.

The relation between the subjective report of memory problems and objective evidence of the same has been debated with mixed results appearing in the literature. Less is known about the relation between objective change in test performance and the perceptions of cognitive change from family members/friends and trained clinicians. These relations were explored using 5-year longitudinal data from the population-based Canadian Study of Health and Aging. Statistically reliable deterioration in memory test performance was determined using a standardized regression-based (SRB) approach and a Reliable Change Index (RCI) that accounts for aging and practice effects. Among a subsample of persons with no cognitive impairment (NCI) at baseline, there was a moderate relation between reliable test score decline and ratings made by clinicians and informants. No relation, however, was found with the subjective reports of memory difficulties. These findings hold implications for current mild cognitive impairment (MCI) criteria which include subjective, informant and/or clinician ratings of cognitive decline.

This article reviews the concept of mild cognitive impairment in groups of people whose cognitive impairment does not warrant a diagnosis of dementia (cognitive impairment, no dementia; CIND). Problems with the application of existing sets of criteria to the Canadian Study of Health and Aging (CSHA) data sets are addressed and a procedure for identifying a subgroup presumed “at risk” for developing dementia is presented. Application of an informant's report of changes in cognitive functioning and neuropsychologists' ratings of mild to severe deficits in any of eight cognitive domains results in approximately half of the CIND cases being identified as “at risk.” The rationale for the collection of specific information related to CIND in CSHA-2 is provided. A minority of people identified with CIND at CSHA-2 showed only memory impairment, and most demonstrated cognitive loss over the preceding five-year interval. This article provides a conceptual basis for procedures to identify people with cognitive impairment most likely to decline to dementia.