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.