Assessment of cross-cultural measurement invariance of the NIH toolbox fluid cognition measures between Jamaicans and African-Americans.

The NIH Toolbox Cognitive Battery (NIHTB-CB) was developed as a common-metric, computerized cognitive screener for research. Although extensively normed and validated in Americans of different ethnicities, there is little data on how generalizable such results would be when used outside of the United States. The objective of this study was to assess measurement invariance (MI) of the NIHTB-CB across Jamaican and African-American samples and determine appropriateness of comparisons across groups. Multi-group confirmatory factor analyses using a single-factor model were conducted using five tests of fluid cognitive abilities from the NIHTB-CB, which assess working memory, episodic memory, processing speed, and executive function. MI was tested sequentially for configural, metric and scalar invariance. 125 Jamaican and 154 American adults of African descent were included. The Jamaican mean age was 31.6 ± 8.6 years (57% males) compared to 43.5 ± 15.5 years (25% males) for the African-American group. The Jamaicans had on average 11.3 ± 2.7 years of education compared to 13.9 ± 2.6 years for the African-Americans. We found metric and configural invariance across both samples but not scalar invariance. These findings suggest that the single factor emerging from the NIHTB-CB measures the same construct, i.e. fluid cognitive ability, in both groups and hence the battery is appropriate for assessments within cultures. However, lack of scalar invariance indicates that direct cross-cultural comparisons of performance levels should be interpreted with caution, also suggesting that U.S. normative standards are not generalizable to the Jamaican population.