Affiliations: [a] Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain | [b] Institut d'Investigacions Biomèdiques 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 Vallés, Barcelona, Spain | [e] Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Barcelona, Spain
Correspondence:
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Correspondence to: Lorena Rami, PhD, Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clínic, Villarroel 170, 08036 Barcelona, Spain. Tel.: +34 932275785; Fax: +34 932275783; E-mail: lrami@clinic.ub.es.
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.
Keywords: Alzheimer's disease, cognition, diagnosis, memory, test
