BackgroundThis study evaluated the diagnostic value and factorial structure of the Subjective Cognitive Decline Questionnaire (SCD-Q) and the Cognitive Failures Questionnaire (CFQ) in the context of early detection of cognitive decline in a memory clinic setting.MethodsA total of 128 patients were included (AD/MCI: n = 50; non-AD dementia: n = 10; mixed dementia: n = 16; subjective cognitive decline SCD: n = 21). Participants completed the modified SCD-Q17 and CFQ and underwent standardized cognitive assessment. Principal component and cluster analyses, regression models, and ROC analyses were used to examine psychometric properties and diagnostic performance.ResultsThe SCD-Q17 correlated with objective cognition (CERAD: r = -0.29 to -0.35, P = 0.023-0.005) and differentiated SCD from mixed dementia (AUC = 0.71). The CFQ primarily reflected executive and attentional failures and showed moderate discrimination for non-AD dementia (SCD vs NADD: AUC = 0.67). Cluster analyses identified 2 profiles (impaired vs unimpaired) for both instruments (κ = 0.47). PCA indicated a more redundant structure for the SCD-Q17, whereas the CFQ showed a broader multidimensional structure.ConclusionsRelative to CERAD performance, both questionnaires distinguished cognitively impaired from unimpaired individuals, but neither provided sufficient precision to classify specific clinical entities.
Tegethoff et al. (Wed,) studied this question.