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

INTRODUCTION The Uniform Data Set (UDS) version 3 neuropsychological battery replaced old tests used in UDS 1&2. Here, we validate domain scores for memory, executive functioning, and language co‐calibrated across UDS eras. METHODS We compared co‐calibrated and harmonized domain scores to traditional equipercentile equating in a crosswalk sample. We also validated domain scores by evaluating associations with magnetic resonance imaging (MRI) findings and APOE genotype across UDS eras. RESULTS We co‐calibrated cognitive domain scores for 49,396 participants, about 25% of whom had data spanning UDS 1&2 and UDS 3 eras. Crosswalk sample ( n = 955) correlations between UDS 1&2 and UDS 3 domain scores and equipercentile scores were similar. Harmonized domain scores had statistically significant associations in imaging ( n = 2458) and APOE validity assessments ( n = 27,857). Significant differences in domain scores were found across UDS eras. DISCUSSION Longitudinal co‐calibrated and harmonized cognitive domain scores bridge the gap across UDS versions and are available from the National Alzheimer's Coordinating Center. Highlights Co‐calibrated domain scores are validated in the NACC crosswalk sample. Co‐calibrated domain scores are validated with neuroimaging measures. Co‐calibrated domains scores are validated with APOE genotype. Co‐calibrated domain scores reveal cognitive performance differences in enrollment visit depending on UDS era. Co‐calibrated domain scores are readily available to investigators utilizing NACC's rich dataset.