Abstract
Background: Subjective cognitive decline (SCD) is increasingly considered
promising to detect preclinical Alzheimer’s disease. How SCD is ascertained is critical
for determining its potential utility in identifying at-risk individuals, yet SCD measures
differ along several dimensions.
Objective: We aimed to examine the extent to which reports of SCD in healthy
elderly may be influenced by the characteristics of the SCD measures. We investigated
variations in rates of SCD endorsement across different measures, including an open-ended
question. We also examined the association of responses across measures, and the degree to
which specific SCD items were associated with objective memory performance.
Methods: 99 healthy elderly completed a series of questionnaires from which
10 items examining SCD for memory and other aspects of cognition were drawn. We applied
Cochran’s Q tests to assess differences in rates of SCD, correlation analyses to examine
association of SCD responses, and regression models to determine the association between
SCD items and delayed verbal memory.
Results: Rates of SCD varied as a function of the assessment format, ranging
from 1 to 7% for memory and 5 to 20% for concentration. SCD was lower for memory versus
non-memory domains. SCD items were associated both within and across domains. The most
accurate predictor of memory was memory-related SCD in comparison to others the same
age.
Conclusion: Characteristics of SCD items influence rates of endorsement.
Querying SCD using an “age-anchored” question may provide the most accurate reflection of
actual cognitive performance.
