Quantitative informant‐ and self‐reports of subjective cognitive decline predict amyloid beta PET outcomes in cognitively unimpaired individuals independently of age and APOE ε4

Introduction Amyloid beta (Aβ) pathology is an Alzheimer's disease early hallmark. Here we assess the value of longitudinal self‐ and informant reports of cognitive decline to predict Aβ positron emission tomography (PET) outcome in cognitively unimpaired middle‐aged individuals. Methods A total of 261 participants from the ALFA+ study underwent [18F]flutemetamol PET and Subjective Cognitive Decline Questionnaire (SCD‐Q) concurrently, and 3 years before scan. We used logistic regressions to evaluate the ability of SCD‐Q scores (self and informant) to predict Aβ PET visual read, and repeated analysis of variance to assess whether changes in SCD‐Q scores relate to Aβ status. Results Self‐perception of decline in memory (odds ratio [OR] = 1.2), and informant perception of executive decline (OR = 1.6), increased the probability of a positive scan. Informant reports 3 years before scanning predicted Aβ PET outcome. Longitudinal increase of self‐reported executive decline was predictive of Aβ in women (P = .003). Discussion Subjective reports of cognitive decline are useful to predict Aβ and may improve recruitment strategies.