TY - JOUR
T1 - Validation of a latent variable representing the dementing process
AU - Royall, Donald R.
AU - Palmer, Raymond F.
AU - O'Bryant, Sidney
PY - 2012/1/1
Y1 - 2012/1/1
N2 - The cognitive correlates of functional status are essential to dementia case-finding. Nevertheless, cognitive performance is a generally weak predictor of functional outcomes. We have employed structural equation models to explicitly distinguish functional status, and therefore "dementia- relevant" variance in cognitive task performance (i.e., δ) from the variance that is unrelated to a dementing process (i.e., g'). Together, g' + δ encompass Spearman's g. Although δ represents only a small fraction of the total variance in cognitive task performance, it is more strongly associated with dementia status than is g'. In this study, we validate δ in a well characterized Alzheimer's disease cohort, the Texas Alzheimer's Research and Care Consortium. Our approach results in "error free" continuous variables. This suggests that δ can serve as a dementia specific endophenotype. As a result, future studies may be able to associate δ with inflammatory and genetic biomarkers.
AB - The cognitive correlates of functional status are essential to dementia case-finding. Nevertheless, cognitive performance is a generally weak predictor of functional outcomes. We have employed structural equation models to explicitly distinguish functional status, and therefore "dementia- relevant" variance in cognitive task performance (i.e., δ) from the variance that is unrelated to a dementing process (i.e., g'). Together, g' + δ encompass Spearman's g. Although δ represents only a small fraction of the total variance in cognitive task performance, it is more strongly associated with dementia status than is g'. In this study, we validate δ in a well characterized Alzheimer's disease cohort, the Texas Alzheimer's Research and Care Consortium. Our approach results in "error free" continuous variables. This suggests that δ can serve as a dementia specific endophenotype. As a result, future studies may be able to associate δ with inflammatory and genetic biomarkers.
KW - Aging
KW - cognition
KW - dementia
KW - functional status
KW - g
UR - http://www.scopus.com/inward/record.url?scp=84862904527&partnerID=8YFLogxK
U2 - 10.3233/JAD-2012-120055
DO - 10.3233/JAD-2012-120055
M3 - Article
C2 - 22451315
AN - SCOPUS:84862904527
SN - 1387-2877
VL - 30
SP - 639
EP - 649
JO - Journal of Alzheimer's Disease
JF - Journal of Alzheimer's Disease
IS - 3
ER -