Estimating premorbid cognitive abilities in low-educated populations

Area of Science:

• Neuroscience
• Psychology
• Gerontology

Background:

• Assessing premorbid cognitive abilities is crucial for understanding cognitive decline.
• Existing methods may not be suitable for low-educated populations.

Purpose of the Study:

• To develop and validate an informant-based instrument for estimating premorbid cognitive abilities in low-educated individuals.

Main Methods:

• Developed the Premorbid Cognitive Abilities Scale (PCAS) with items on education, occupation, and daily cognitive tasks.
• Validated the PCAS in older Brazilian adults with normal cognition, mild cognitive impairment, and mild dementia.
• Assessed inter-informant reliability using relatives of deceased individuals.

Main Results:

• The PCAS demonstrated good item discriminative power.
• The scale showed high correlations with global cognitive function (r=0.73) and reading skills (r=0.82).
• Achieved excellent internal consistency (Cronbach's alpha=0.90) and inter-informant reliability (ICC=0.96).

Conclusions:

• The PCAS is a valid and reliable tool for estimating premorbid cognitive abilities in low-educated populations.
• The scale can be utilized to assess premorbid intelligence and cognitive reserve.