Identifying Predictors of Reversion from Mild Cognitive Impairment to Normal Cognition

Studies on mild cognitive impairment (MCI) have focused on identifying predictors of progression to dementia, yet relatively few studies have examined predictors of reversion from MCI to normal cognition. This retrospective study incorporated data from the National Alzheimer's Coordinating Center Uniform Data Set to examine baseline predictors of MCI reversion. A total of 1,208 participants meeting MCI criteria were evaluated at baseline visit and three subsequent annual visits. Of these, 175 (14%) reverted to normal cognition, 612 (51%) remained MCI, and 421 (35%) progressed to dementia at two-years, with sustained diagnoses at three-years. This study only examined MCI participants who reverted to normal cognition (175) and progressed to dementia (421) for a final total of 596 participants. Baseline predictors of MCI reversion were categorized into the clusters of demographic/genetic data, global functioning, neuropsychological functioning, medical health/dementia risk score, and neuropsychiatric symptoms. Binary stepwise logistic regression models were used to identify significant predictors of MCI reversion compared to MCI progression for each cluster, which were then entered into a final comprehensive model to find the overall significant predictor(s). Receiver operating characteristic (ROC) curves were then used to determine cut-off scores for the continuous predictors most significant for MCI reversion. The variables most significantly associated with MCI reversion were younger age, being unmarried, having zero copies of the APOE ε4 allele, lower Clinical Dementia Rating Sum of Boxes scores, and higher test scores on Logical Memory Delayed Recall, Vegetable Fluency, and Boston Naming Test at baseline. ROC curve results revealed a standard z-score of -1.16 or better on Logical Memory Delayed Recall as an accurate classification of the MCI reversion group from the MCI progression group, with 89% sensitivity and 73% specificity. Results suggest that demographic, global functioning, and neuropsychological factors are significantly associated with MCI reversion. Future longitudinal studies on MCI reversion, with a multifactorial approach, are necessary to increase understanding of MCI reversion. Findings could help educate patients and families on clinical outcomes of MCI, better inform healthcare providers on treatment management and clinical prognosis, and increase precision of findings in early intervention studies of dementia.