An approach to classifying subjective cognitive decline in community-dwelling elders

Introduction: Subjective cognitive decline (SCD) may be an early symptomatic manifestation of Alzheimer's disease, though published research largely neglects how to classify SCD in community-based studies. Methods: In neuropsychologically intact Einstein Aging Study participants (n = 1115; mean age = 78; 63% female; 30% non-White), we used Cox models to examine the association between self-perceived cognitive functioning at baseline (using three different approaches) and incident amnestic mild cognitive impairment (aMCI) with covariates of age, sex, education, race/ethnicity, general (objective) cognition, depressive symptoms, and four other SCD-related features. Results: After a median of 3 years, 198 participants developed aMCI. In models that included all the variables, self-perceived cognitive functioning was consistently associated with incident aMCI as were age, general cognition, and perceived control; apolipoprotein E (APOE) ε4 allele status was significant in one model. We set cut points that optimized the diagnostic accuracy of SCD at various time frames. Discussion: We provide an approach to SCD classification and discuss implications for cognitive aging studies.