A Pattern of Relatively Conserved Fluency Indicates Preclinical Minor Cognitive Decline

Objective: When neuropsychological testing is used for medical assessment of cognition, individual differences in premorbid ability may not be accounted for, leaving some individuals at risk for under-detection of impairment. We investigated whether patterns of relative performance in different cognitive domains could be used to detect early-stage cognitive decline in the absence of baseline performance data and irrespective of individual differences in overall performance. Method: In an exploratory secondary analysis of data from 200 older adults followed longitudinally, we used profile analysis to compare the domain-specific performance of those who experienced minor cognitive decline over a 12-to-18-month interval with those who did not experience decline. Results: We found that having experienced minor cognitive decline in the preceding 12 to 18 months was associated with a pattern of higher performance in fluency relative to performance in six other cognitive domains. In our study, this pattern of relative performance could be used to identify recent decline with 79.5% accuracy, 95% CI [73.2%, 84.9%], even without knowledge of overall performance. However, individuals who performed in the top third at baseline could not be shown to exhibit the same pattern of cross-domain cognitive performance following decline. Conclusions: A pattern of higher performance in fluency relative to other cognitive domains may indicate recent minor cognitive decline. Results suggest that knowledge of a patient’s baseline cognitive ability or intelligence can inform the interpretation of neuropsychological test results. This study should be replicated using a dataset for which early adulthood cognitive scores are available.