Race/ethnicity and the measurement of cognition in NSHAP: Recommendations for robustness.

Objectives: In this study, we examine the measurement of cognition in different racial/ethnic groups to move towards a less biased and more inclusive set of measures for capturing cognitive change and decline in older adulthood.

Methods: We use data from Round 2 (N=3377) and Round 3 (N=4777) of the National Social Life, Health, and Aging Project (NSHAP) and examine the study's Survey Adjusted version of the Montreal Cognitive Assessment (MoCA-SA). We employ exploratory factor analyses to explore configural invariance by racial/ethnic group. Using modification indexes, two-parameter item response theory models, and split-sample testing, we identify items that seem robust to bias by race. We test the predictive validity of the full (18-item) and short (4-item) MoCA-SAs using self-reported dementia diagnosis, instrumental activities of daily living (IADLs), proxy reports of dementia, proxy reports of dementia-related death, and National Death Index reports of dementia-related death.

Results: We found that four measures out of the 18 used in NSHAP's MoCA-SA formed a scale that was more robust to racial bias. The shortened form predicted consequential outcomes as well as NSHAP's full MoCA-SA. The short form was also moderately correlated with the full form.

Discussion: Although sophisticated structural equation modeling techniques would be preferrable for assuaging measurement invariance by race in NSHAP, the shortened form of the MoCA-SA provides a quick way for researchers to carry out robustness checks and to see if the disparities and associations by race they document are "real" or the product of artifactual bias.