Cognitive Performance among Cognitively Healthy Adults Aged 30-100 Years

To detect cognitive decline in older adults, measures of verbal fluency and verbal memory are widely used. Less is known about performance in these measures in younger persons or according to education level and gender. We investigated cognitive performance according to age, education and gender among cognitively healthy adults aged 30-100 years.

The study population comprised 4,174 cognitively healthy persons participating in the nationally representative Finnish Health 2011 survey. Cognitive assessment included verbal fluency, word list memory, word list recall and word list savings from the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery.

Total variance in the cognitive test performance explained by age, education and gender varied from 12.3 to 31.2%. A decreasing trend in cognitive performance existed in all subtests by advancing age, with differences appearing between 50 and 55 years. Persons with the highest-education level performed best for all measures. For the participants < 55 years, education explained part of the variance, while age and gender did not.

When assessing cognition, age and education should be accounted for in more detail in research and clinical practice. Additionally, the cohort effect and its potential impact on the renewal cycle of future normative values for cognitive tests should be considered.