Longitudinal change in neuropsychological performance using latent growth models: a study of mild cognitive impairment

Abstract

The goal of the current study was to examine cognitive change in both healthy controls (n=229) and individuals with mild cognitive impairment (MCI) (n=397) from the Alzheimer's Disease Neuroimaging Initiative (ADNI). We applied latent growth modeling to examine baseline and longitudinal change over 36 months in five cognitive factors derived from the ADNI neuropsychological test battery (memory, executive function/processing speed, language, attention and visuospatial). At baseline, MCI patients demonstrated lower performance on all of the five cognitive factors when compared to controls. Both controls and MCI patients declined on memory over 36 months; however, the MCI patients declined at a significantly faster rate than controls. The MCI patients also declined over 36 months on the remaining four cognitive factors. In contrast, the controls did not exhibit significant change over 36 months on the non-memory cognitive factors. Within the MCI group, executive function declined faster than memory, while the other factor scores changed slower than memory over time. These findings suggest different patterns of cognitive change in healthy older adults and MCI patients. The findings also suggest that, when compared with memory, executive function declines faster than other cognitive factors in patients with MCI. Thus, decline in non-memory domains may be an important feature for distinguishing healthy older adults and persons with MCI.

Assessment of planning abilities in individuals with mild cognitive impairment using an open-ended problem-solving task

“…Consistent with evidence that individuals with MCI experience changes in cognitive areas beyond memory (Aretouli & Brandt, 2010;Brandt et al, 2009;Clark et al, 2012;Johns et al, 2012;Johnson, 2012;Schmitter-Edgecombe & Sanders, 2009;Tabert et al, 2006;Yanhong et al, 2013;Zhang et al, 2007), our findings revealed that MCI participants performed more poorly than OAs on several standardized measures of executive functioning (Trails B, D-KEFS Letter Fluency and Design Fluency). However, correlational analyses revealed no significant associations between the Amap measures and these standardized measures of executive function.…”

Application of Latent Variable Methods to the Study of Cognitive Decline When Tests Change over Time

“…In addition to GEE methods using factor scores, we estimated the association of diabetes with cognitive decline simultaneously with the factor analysis in a structural equations model specifying a latent growth curve across the factors (Supplemental Figure 1)(37). In another sensitivity analysis, we compared associations between diabetes and general cognitive performance based on all available tests to associations based on a model using only the three tests administered at all study visits.…”

Predictors of Retest Effects in a Longitudinal Study of Cognitive Aging in a Diverse Community-Based Sample

“…This scaling approach does not make the WHICAP sample nationally representative, but it allows future analysts, using other datasets with items overlapping with ADAMS, to derive directly comparable scores. This approach assumes measurement invariance of factors with respect to time: an assumption previously verified in other samples of older adults and which we evaluated in WHICAP through formal tests described earlier (Hayden et al, 2011; Johnson et al, 2012). We additionally tested longitudinal measurement invariance of the factors among participants assessed at baseline and whose second study visit was between 1.5 and 2.5 years later (median: 2.1 years) using multiple group confirmatory factor analysis models.…”

“…To test hypotheses, we used multilevel models with random effects for people and time alongside fixed effects for retest in general cognition, memory, executive functioning, and language (Johnson et al, 2012; Laird & Ware, 1982; Muthen et al, 1997; Raudenbush & Bryk, 2002). Time since enrollment into the study was the timescale of interest.…”