Bridging the gap: addressing NACC's evolving cognition batteries across UDS versions

Area of Science:

• Neuroscience
• Cognitive Science
• Biostatistics

Background:

• The Uniform Data Set (UDS) neuropsychological battery was updated in version 3, replacing older tests from UDS 1 & 2.
• This transition necessitates validation of cognitive domain scores across different UDS versions to ensure data continuity.

Purpose of the Study:

• To validate co-calibrated and harmonized cognitive domain scores for memory, executive functioning, and language across UDS versions.
• To assess the reliability of these scores using crosswalk samples, neuroimaging data, and APOE genotype.

Main Methods:

• Co-calibration and harmonization of cognitive domain scores for 49,396 participants.
• Comparison of co-calibrated scores with traditional equipercentile equating in a crosswalk sample (n=955).
• Validation of domain scores through associations with magnetic resonance imaging (MRI) findings (n=2458) and APOE genotype (n=27,857).

Main Results:

• Co-calibration included approximately 25% of participants with data spanning UDS 1&2 and UDS 3.
• Correlations between UDS 1&2 and UDS 3 domain scores and equipercentile scores were comparable.
• Harmonized scores showed significant associations with neuroimaging and APOE genotype, and revealed cognitive performance differences across UDS eras.

Conclusions:

• Longitudinal co-calibrated and harmonized cognitive domain scores effectively bridge data gaps between UDS versions.
• These validated scores are accessible through the National Alzheimer's Coordinating Center (NACC) for Alzheimer's disease research.