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Quality of life in patients with cognitive impairment: validation of the Quality of Life–Alzheimer's Disease scale in Portugal

Published online by Cambridge University Press:  27 March 2013

Helena Bárrios*
Dementia Group, Institute of Molecular Medicine and Faculty of Medicine, University of Lisbon, Lisbon, Portugal Hospital do Mar, Lisbon, Portugal
Ana Verdelho
Laboratory of Neurosciences, Institute of Molecular Medicine and Faculty of Medicine, University of Lisbon, Lisbon, Portugal
Sofia Narciso
Dementia Group, Institute of Molecular Medicine and Faculty of Medicine, University of Lisbon, Lisbon, Portugal
Manuel Gonçalves-Pereira
CEDOC, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
Rebecca Logsdon
School of Nursing, University of Washington, Seattle, Washington, USA
Alexandre de Mendonça
Laboratory of Neurosciences, Institute of Molecular Medicine and Faculty of Medicine, University of Lisbon, Lisbon, Portugal
Correspondence should be addressed to: Helena Bárrios, Hospital do Mar, Rua dos Girassóis, 6 e 6A, 2695-458 Bobadela, Portugal. Phone: 351-2-19948660; Fax: 351-2-19948679. Email:


Background: Quality of Life–Alzheimer's Disease (QOL-AD) is a widely used scale for the study of quality of life in patients with dementia. The aim of this study is the transcultural adaptation and validation of the QOL-AD scale in Portugal.

Methods: Translation and transcultural adaptation was performed according to state-of-the-art recommendations. For the validation study, 104 patient/caregiver pairs were enrolled. Patients had mild cognitive impairment or mild-to-moderate dementia (due to Alzheimer's disease or vascular dementia). Participants were recruited in a dementia outpatient clinic setting and a long-term care dementia ward. An additional comparison group of 22 patients without cognitive impairment, and their proxies, was recruited in a family practice outpatient clinic. Sociodemographic information on patients and caregivers was obtained. Acceptability, reliability, and construct validity were analyzed.

Results: Internal consistency of the Portuguese version of QOL-AD was good for both patient and caregiver report (Cronbach's α = 0.867 and 0.858, respectively). Construct validity was confirmed by the correlation of patient reported QOL-AD with patient geriatric depression scale scores (ρ = −0.702, p < 0.001) and satisfaction with life scale scores (ρ = 0.543, p < 0.001). Caregiver ratings were correlated with neuropsychiatric inventory (NPI) total score (ρ = −0.404, p < 0.001), NPI-distress (ρ = −0.346, p < 0.001), and patient Mini-Mental State Examination (ρ = 0.319, p < 0.01). QOL-AD patient ratings were higher than caregiver ratings (p < 0.001). Both patient- and caregiver-rated QOL-AD scores were lower in patients with cognitive impairment than in the comparison group without cognitive impairment (p < 0.01).

Conclusions: A Portuguese version of QOL-AD with consistent psychometric properties was obtained and is proposed as a useful tool for research and clinical purposes.

Research Article
Copyright © International Psychogeriatric Association 2013 

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