Few studies on instruments for staging frontotemporal dementia (FTD) have been conducted.
The objective of this study was to analyze the factor structure, internal consistency, reliability, and convergent validity of the Brazilian version of the Frontotemporal Dementia Rating Scale (FTD-FRS).
A total of 97 individuals aged 40 years and above with >2 years’ education took part in the study, 31 patients diagnosed with behavioral variant FTD (bvFTD), 8 patients with primary progressive aphasia, 28 with Alzheimer disease, 8 with mild cognitive impairment, and a control group of 22 healthy subjects. The FTD-FRS was completed by family members or caregivers, and Neurologists completed the 8-item Clinical Dementia Rating for Frontotemporal Lobar Degeneration (CDR-FTLD) scale (6 original domains plus Language and Behavior). The Alzheimer disease and FTD patients had equivalent disease severity level.
The internal consistency of the FTD-FRS, estimated by Cronbach α, was 0.975 whereas test-retest reliability was 0.977. Scree plot and exploratory factor (Varimax rotation) analyses revealed the existence of 4 factors, with eigenvalues >1, which together explained 77.13% of the total variance with values of 1.28 to 17.52. The domains of the Brazilian version of the FTD-FRS scale correlated with the domains of the CDR-FTLD.
The present study is the first to document the factorial structure of the FTD-FRS and its convergent validity with the CDR-FTLD. These tools are key to determine dementia severity in FTD. The Brazilian FTD-FRS demonstrated adequate psychometric properties for use in Brazil. This instrument may contribute to disease staging in FTD and may help to document intervention-related changes.
*Neurology Department, University of São Paulo
†Cognitive and Behavioral Neurology Research Group, School of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais (MG), Brazil
‡Neurology Department, University of Campinas, São Paulo
§School of Health Sciences, University of East Anglia, Norwich, United Kingdom
T.B.L.-S.: received financial support from CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), process number 151684/2014-6 and from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Brazil (CAPES: 88881.131619/2016-01). P.C., R.N., and M.S.Y.: also are funded by CNPq, Brazil.
The authors declare no conflicts of interest.
Reprints: Mônica S. Yassuda, PhD, Av. Dr. Eneas de Carvalho Aguiar, 255, School of Medicine, University of São Paulo, São Paulo, SP 05403-100, Brazil (e-mail: firstname.lastname@example.org).
Received August 21, 2017
Accepted December 30, 2017