Exploring the factor structure of neurocognitive measures in older individuals

Nadine Correia Santos; Patrício Soares Costa; Liliana Amorim; Pedro Silva Moreira; Pedro Cunha; Jorge Cotter; Nuno Sousa

doi:10.1371/journal.pone.0124229

Exploring the factor structure of neurocognitive measures in older individuals

PLoS One. 2015 Apr 16;10(4):e0124229. doi: 10.1371/journal.pone.0124229. eCollection 2015.

Authors

Nadine Correia Santos¹, Patrício Soares Costa¹, Liliana Amorim¹, Pedro Silva Moreira¹, Pedro Cunha², Jorge Cotter², Nuno Sousa¹

Affiliations

¹ Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal; ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal.
² Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal; ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal; Centro Hospitalar do Alto Ave-EPE, Guimarães, Portugal.

Abstract

Here we focus on factor analysis from a best practices point of view, by investigating the factor structure of neuropsychological tests and using the results obtained to illustrate on choosing a reasonable solution. The sample (n=1051 individuals) was randomly divided into two groups: one for exploratory factor analysis (EFA) and principal component analysis (PCA), to investigate the number of factors underlying the neurocognitive variables; the second to test the "best fit" model via confirmatory factor analysis (CFA). For the exploratory step, three extraction (maximum likelihood, principal axis factoring and principal components) and two rotation (orthogonal and oblique) methods were used. The analysis methodology allowed exploring how different cognitive/psychological tests correlated/discriminated between dimensions, indicating that to capture latent structures in similar sample sizes and measures, with approximately normal data distribution, reflective models with oblimin rotation might prove the most adequate.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Factor Analysis, Statistical
Female
Humans
Male
Middle Aged
Neurocognitive Disorders / physiopathology*
Neuropsychological Tests*
Principal Component Analysis

Grants and funding

The study is integrated in the ‘‘Maintaining health in old age through homeostasis (SWITCHBOX)’’ (http://www.switchbox-online.eu/) collaborative project funded by the European Commission FP7 initiative (grant HEALTH-F2-2010-259772) and co-financed by the Portuguese North Regional Operational Program (ON.2 – O Novo Norte) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER). NCS is supported by a SwitchBox post-doctoral fellowship, LA and PSM are supported by "MyHealth” project (Contract DoIT-13853)" doctoral fellowships. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.