Development of a latent dementia index in the aging, demographics, and memory study: Validation and measurement invariance by sex

Latent variable models can create a latent dementia index (LDI) using cognitive and functional ability to approximate dementia likelihood. The LDI approach has been applied across diverse cohorts. It is unclear whether sex affects its measurement properties. We use Wave A (2001-2003) of the Aging, Demographics, and Memory Study (n = 856). Multiple group confirmatory factor analysis (CFA) was used to test measurement invariance (MI) using informant-reported functional ability and cognitive performance tasks, which we group into verbal, nonverbal, and memory. Partial scalar invariance was found, allowing for testing sex differences in LDI means (M-Diff = 0.38). The LDI correlated with consensus panel dementia diagnosis, Mini-Mental State Examination (MMSE), and dementia risk factors (low education, advanced age, and apolipoprotein epsilon 4 [APOE-epsilon 4] status) for men and women. The LDI validly captures dementia likelihood to permit estimation of sex differences. LDI sex differences indicate higher dementia likelihood in women, potentially due to social, environmental, and biological factors.