Predicting progression from mild cognitive impairment to dementia with baseline neuropsychological test scores

BackgroundAlthough neuropsychological scores have predicted progression from mild cognitive impairment (MCI) to dementia, past work has limitations, including small samples, limited batteries, and research cohorts.ObjectiveThis study sought to identify which baseline cognitive scores predicted progression in clinical patients with MCI followed over 1.5 years.Methods243 individuals clinically diagnosed with MCI at a baseline visit completed neuropsychological testing at baseline and were followed approximately 1.5 years later. Using follow-up diagnoses from neurologists, they were grouped as "MCI-Stable" (i.e., MCI at baseline and follow-up, n = 131) or "MCI-Progressors" (i.e., MCI at baseline but dementia at follow-up, n = 112). Stepwise logistic regression examined follow-up group status predicted from demographics, baseline cognitive scores, and self-reported depressive symptoms.ResultsNeither baseline demographic variables nor depressive symptoms significantly predicted group status at follow-up. Conversely, worse baseline performance on tests of visuospatial construction and semantic fluency were significant predictors of progression from MCI to dementia. Longer follow-up interval also significantly predicted conversion.ConclusionsAlthough many individuals progress from MCI to dementia, there is considerable variability in the timing and cognitive performance among those who convert to dementia versus those who remain stable over time. The current findings identified multiple baseline neuropsychological test scores that predicted that progression over approximately 1.5 years. Such results have implications for clinical care (e.g., providing more services and closer monitoring of at-risk individuals) and research (e.g., enriching clinical trials with those more likely to progress).