Questioning the Meaning of a Change on the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog): Noncomparable Scores and Item-Specific Effects Over Time.

ABSTRACT: Longitudinal invariance indicates that a construct is measured over time in the same way, and this fundamental scale property is a sine qua non to track change over time using ordinary mean comparisons. The Alzheimer's Disease Assessment Scale-cognitive (ADAS-Cog) and its subscale scores are often used to monitor the progression of Alzheimer's disease, but longitudinal invariance has not been formally evaluated. A configural invariance model was used to evaluate ADAS-Cog data as a three correlated factors structure for two visits over 6 months, and four visits over 2 years (baseline, 6, 12, and 24 months) among 341 participants with Alzheimer's disease. We also attempted to model ADAS-Cog subscales individually, and furthermore added item-specific latent variables. Neither the three

SUBMITTER: Cogo-Moreira H 

PROVIDER: S-EPMC8392777 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature