Longitudinal measurement invariance of neuropsychological tests in a diverse sample from the ELSA-Brasil study.

OBJECTIVE

Longitudinal measurement invariance analyses are an important way to assess a test's ability to estimate the underlying construct over time, ensuring that cognitive scores across visits represent a similar underlying construct, and that changes in test performance are attributable to individual change in cognitive abilities. We aimed to evaluate longitudinal measurement invariance in a large, social and culturally diverse sample over time.

METHODS

A total of 5,949 participants from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) were included, whose cognition was reassessed after four years. Longitudinal measurement invariance analysis was performed by comparing a nested series of multiple-group confirmatory factor analysis models (for memory and executive function factors).

RESULTS

Configural, metric, scalar and strict invariance were tested and supported over time.

CONCLUSION

Cognitive temporal changes in this sample are more likely to be due to normal and/or pathological aging. Testing longitudinal measurement invariance is essential for diverse samples at high risk of dementia, such as in low- and middle-income countries.