Psychometric Characteristics of the Novel Subjective Cognitive Changes Questionnaire (SCC‐Q) in Older Adults at Risk of Dementia

Abstract

AbstractBackgroundSubjective cognitive complaints (SCC) in the elderly may represent an early cognitive marker of Alzheimer’s disease (AD). Currently, there is no recommended gold standard for evaluating SCC. In addition, available questionnaires were originally developed to identify individuals at later stages of AD. Based on previous research, we constructed the Subjective Cognitive Changes Questionnaire (SCC‐Q), which includes items potentially sensitive to early cognitive decline. The study aimed to analyse reliability of the individual items and construct and convergent validity of the SCC‐Q.MethodA total of 211 non‐demented participants over the age of 55 from the Czech Brain Aging Study (CBAS) underwent a comprehensive neuropsychological examination, based on which they were classified into two groups: patients with amnestic mild cognitive impairment (n = 88) and those with subjective cognitive decline (SCD) (n = 88). Further, we included cognitively healthy volunteers without SCC (n = 35). All participants completed the novel 26‐item SCC‐Q in which they evaluated change in specific cognitive abilities during the last 5 years on a 5‐point Likert scale. The structure of the SCC‐Q was explored using the principal component analysis (PCA) with varimax rotation. To analyse associations between the components and cognitive performance (convergent validity), non‐parametric partial rank correlations controlled for sex, age and education were performed. Cognitive performance was expressed as composite z‐scores representing memory, attention and working memory, language, executive, and visuospatial function.ResultItem analysis showed that all included items were highly reliable (McDonald’s Ω > 0.9, Cronbach’s α > 0.9). Using the PCA, four components explaining 57.6% of the variance were identified. Two of them were significantly associated with memory, attention and working memory, and executive or visuospatial function, respectively (all ps ≤ 0.048). The component more closely associated with cognitive domains includes items related to spatial orientation changes.ConclusionThe SCC‐Q has the potential to become a valuable method for clinical practice in identifying individuals at risk of developing cognitive deficits. Further analyses are needed to confirm its validity.