Changes in self- and study partner?perceived cognitive functioning in relation to amyloid status and future clinical progression: Findings from the SCIENCe project

Introduction: We investigated changes in self- and study partner?reported self-perceived cognitive decline in relation to amyloid pathology and clinical progression, in a sample of cognitively normal individuals. Methods: A total of 404 participants (63???9 years, 44% female) and their study partners completed the Cognitive Change Index (CCI) yearly (0.7?6.8 follow-up years; n visits?=?1436). Baseline and longitudinal associations between (change in) CCI scores, amyloid, and clinical progression were modeled in linear mixed models and Cox regressions. Results: CCI?study partner scores of amyloid-positive individuals increased over time (B?=?1.79, 95% confidence interval [CI]?=?[0.51, 3.06]), while CCI?self scores remained stable (B?=??0.45, 95% CI?=?[?1.77, 0.87]). Ten-point higher baseline CCI?study partner (hazard ratio [HR]?=?1.75, 95% CI?=?[1.30, 2.36]) and CCI?self scores (HR?=?1.90, 95% CI?=?[1.40, 2.58]) were associated with an approximately 2-fold increased risk of progression to mild cognitive impairment or dementia. Discussion: Study partner?reported but not self-perceived complaints increase over time in amyloid-positive individuals, supporting the value of longitudinal study partner report, even in initially cognitively normal individuals.