title: The Subjective Cognitive Decline Questionnaire (SCD-Q): a validation study.
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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Rami
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Mollica
authors.affiliation: Memory Unit. Neurology Service. Hospital Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: García-Sanchez
authors.affiliation: Hospital de Mollet del Vallés, Barcelona, Spain.
authors.forename: Judith
authors.initials: J
authors.lastname: Saldaña
authors.affiliation: Memory Unit. Neurology Service. Hospital Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: Belen
authors.initials: B
authors.lastname: Sanchez
authors.affiliation: Memory Unit. Neurology Service. Hospital Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Sala
authors.affiliation: Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Barcelona, Spain.
authors.forename: Cinta
authors.initials: C
authors.lastname: Valls-Pedret
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
authors.forename: Magda
authors.initials: M
authors.lastname: Castellví
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Olives
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Molinuevo
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000523:psychology; D001007:Anxiety; D017028:Caregivers; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000523:psychology; D003863:Depression; D056344:Executive Function; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D012649:Self Concept; D057566:Self Report; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires
keywords: Alzheimer's disease; cognition; diagnosis; memory; test