Analysis of the Relationship of Cognitive Impairment and Functional Impairment in Mild Alzheimer’s Disease in EXPEDITION 3

BackgroundClinical progression of Alzheimer’s disease is characterized by impairment in cognition and function.ObjectiveTo assess the relationship between cognitive and functional impairment in mild Alzheimer’s disease.DesignSpearman’s rank correlations between cognitive and functional measures were calculated. Autoregressive cross-lagged panel analyses were used to determine the temporal relationship between cognitive and functional decline.SettingPost-hoc analysis of clinical trial data.ParticipantsPlacebo-treated patients with mild Alzheimer’s disease from the Phase 3 solanezumab study EXPEDITION 3.InterventionPlacebo.MeasurementsCognitive and functional measures were assessed at baseline and at six post-baseline time points through Week 80.ResultsCorrelation between cognitive and functional measures was 0.41 at baseline and 0.65 at Week 80. Autoregressive cross-lagged panel analysis demonstrated that cognitive impairment preceded and predicted subsequent functional decline, but functional scores did not predict cognitive outcomes.ConclusionsThis study supports the hypothesis that functional impairment predictably follows cognitive decline in mild Alzheimer’s disease dementia.