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 (Aß) pathology is an Alzheimer's disease early hallmark. Here we assess the value of longitudinal self- and informant reports of cognitive decline to predict Aß 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 Aß PET visual read, and repeated analysis of variance to assess whether changes in SCD-Q scores relate to Aß 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 Aß PET outcome. Longitudinal increase of self-reported executive decline was predictive of Aß in women (P = .003). DISCUSSION: Subjective reports of cognitive decline are useful to predict Aß and may improve recruitment strategies.