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Journal of Alzheimer’s Disease xx (20xx) x–xx DOI 10.3233/JAD-132027 IOS Press
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The Subjective Cognitive Decline Questionnaire (SCD-Q): A Validation Study
roo f
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a Alzheimer’s
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b Institut
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uth
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Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain d’Investigacions Biom`ediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain c Memory Unit. Neurology Service. Hospital Santa Creu i Sant Pau, Barcelona, Spain d Hospital de Mollet del Vall´ es, Barcelona, Spain e Lipid Clinic, Endocrinology and Nutrition Service, Hospital Cl´ınic, Barcelona, Spain Handling Associate Editor: Montse Alegret
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Lorena Ramia,b,∗ , Maria A. Mollicaa , Carmen Garc´ıa-Sanchezc , Judith Salda˜nad , Belen Sanchezc , Isabel Salac , Cinta Valls-Pedretb,e , Magda Castellv´ıa,b , Jaume Olivesa and Jose L. Molinuevoa,b
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Accepted 2 February 2014
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Keywords: Alzheimer’s disease, cognition, diagnosis, memory, test
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rre
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co
13
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cte
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Abstract. Background: Subjective cognitive decline (SCD) is gaining importance as a focus of investigation, but adequate tools are needed for its quantification. Objective: To develop and validate a questionnaire to quantify SCD, termed the Subjective Cognitive Decline Questionnaire (SCD-Q). Methods: 124 controls (CTR), 144 individuals with SCD, 83 mild cognitive impairment subjects, 46 Alzheimer’s disease patients, and 397 informants were included. The SCD-Q contains: part I, named MyCog, which is answered by the subject; and part II, TheirCog, which includes the same questions and is answered by the informant or caregiver. The 24 SCD-Q items assess the perceived subjective decline in memory, language, and executive functions in the last two years. Results: The MyCog scores of controls differed significantly from those of the other groups (p < 0.05) and there were significant differences in TheirCog scores between all groups. The optimal TheirCog cut-off score for discriminating between individuals with and without cognitive impairment was 7/24 (sensitivity 85%, specificity 80%). MyCog scores correlated significantly with anxiety and depression (r = 0.29, r = 0.43, p < 0.005), but no correlations were found with neuropsychological tests. TheirCog scores correlated significantly with most of the neuropsychological tests (p < 0.05). Informants’ depression and anxiety influenced TheirCog scores in controls and SCD groups. Conclusion: Self-perceived cognitive decline, measured by the SCD-Q part I (MyCog), discriminated SCD from CTR. Part II (TheirCog) was strongly related to subjects’ objective cognitive performance, and discriminated between subjects with or without cognitive impairment. The SCD-Q is a useful tool to measure self-perceived cognitive decline incorporating the decliner and the informant perspective.
11
INTRODUCTION
∗ Correspondence
to: Lorena Rami, PhD, Alzheimer’s Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Cl´ınic, Villarroel 170, 08036 Barcelona, Spain. Tel.: +34 932275785; Fax: +34 932275783; E-mail: [email protected].
In the attempts to define the earliest symptoms of the Alzheimer’s disease (AD) continuum, self-perceived cognitive decline represents an increasingly important focus of research [1–4]. There is now a clear need to develop instruments able to quantify subjective
ISSN 1387-2877/14/$27.50 © 2014 – IOS Press and the authors. All rights reserved
31
32 33 34 35 36
Journal of Alzheimer’s Disease xx (20xx) x–xx DOI 10.3233/JAD-132027 IOS Press
2
The Subjective Cognitive Decline Questionnaire (SCD-Q): A Validation Study
roo f
1
5
a Alzheimer’s
6
b Institut
9
10
uth
8
Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain d’Investigacions Biom`ediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain c Memory Unit. Neurology Service. Hospital Santa Creu i Sant Pau, Barcelona, Spain d Hospital de Mollet del Vall´ es, Barcelona, Spain e Lipid Clinic, Endocrinology and Nutrition Service, Hospital Cl´ınic, Barcelona, Spain Handling Associate Editor: Montse Alegret
dA
7
or P
4
Lorena Ramia,b,∗ , Maria A. Mollicaa , Carmen Garc´ıa-Sanchezc , Judith Salda˜nad , Belen Sanchezc , Isabel Salac , Cinta Valls-Pedretb,e , Magda Castellv´ıa,b , Jaume Olivesa and Jose L. Molinuevoa,b
3
Accepted 2 February 2014
30
Keywords: Alzheimer’s disease, cognition, diagnosis, memory, test
15 16 17 18 19 20 21 22 23 24 25 26 27 28
rre
14
co
13
Un
12
cte
29
Abstract. Background: Subjective cognitive decline (SCD) is gaining importance as a focus of investigation, but adequate tools are needed for its quantification. Objective: To develop and validate a questionnaire to quantify SCD, termed the Subjective Cognitive Decline Questionnaire (SCD-Q). Methods: 124 controls (CTR), 144 individuals with SCD, 83 mild cognitive impairment subjects, 46 Alzheimer’s disease patients, and 397 informants were included. The SCD-Q contains: part I, named MyCog, which is answered by the subject; and part II, TheirCog, which includes the same questions and is answered by the informant or caregiver. The 24 SCD-Q items assess the perceived subjective decline in memory, language, and executive functions in the last two years. Results: The MyCog scores of controls differed significantly from those of the other groups (p < 0.05) and there were significant differences in TheirCog scores between all groups. The optimal TheirCog cut-off score for discriminating between individuals with and without cognitive impairment was 7/24 (sensitivity 85%, specificity 80%). MyCog scores correlated significantly with anxiety and depression (r = 0.29, r = 0.43, p < 0.005), but no correlations were found with neuropsychological tests. TheirCog scores correlated significantly with most of the neuropsychological tests (p < 0.05). Informants’ depression and anxiety influenced TheirCog scores in controls and SCD groups. Conclusion: Self-perceived cognitive decline, measured by the SCD-Q part I (MyCog), discriminated SCD from CTR. Part II (TheirCog) was strongly related to subjects’ objective cognitive performance, and discriminated between subjects with or without cognitive impairment. The SCD-Q is a useful tool to measure self-perceived cognitive decline incorporating the decliner and the informant perspective.
11
INTRODUCTION
∗ Correspondence
to: Lorena Rami, PhD, Alzheimer’s Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Cl´ınic, Villarroel 170, 08036 Barcelona, Spain. Tel.: +34 932275785; Fax: +34 932275783; E-mail: [email protected].
In the attempts to define the earliest symptoms of the Alzheimer’s disease (AD) continuum, self-perceived cognitive decline represents an increasingly important focus of research [1–4]. There is now a clear need to develop instruments able to quantify subjective
ISSN 1387-2877/14/$27.50 © 2014 – IOS Press and the authors. All rights reserved
31
32 33 34 35 36
