Estimating Progression Rates Across the Spectrum of Alzheimer’s Disease for Amyloid-Positive Individuals Using National Alzheimer’s Coordinating Center Data

INTRODUCTION: Published estimates of Alzheimer’s disease (AD) progression do not capture the full disease continuum. This study provides transition probabilities of individuals with amyloid-β (Aβ+) pathology across the disease continuum. METHODS: Patient-level longitudinal data from the National Alzheimer’s Coordinating Center were used to estimate progression rates. Progression rates through five clinically defined AD stages—asymptomatic, mild cognitive impairment due to AD (MCI-AD), mild AD dementia, moderate AD dementia, severe AD dementia—and death were measured as transition probabilities. Rates were assessed in “incident” patients who recently entered the stage, controlling for covariates. Transition probabilities were generated from multinomial logit regression models that predicted an individual’s health state as a function of health state at the previous visit and adjusted for time between initial and follow-up visits, age, sex, years of education, and concomitant symptomatic AD medications. RESULTS: Annual transition probabilities to more severe dementia stages for surviving incident Aβ+ patients were as follows: asymptomatic to MCI-AD, 40.8%; MCI-AD to mild AD dementia or worse, 21.8%; mild AD dementia to moderate AD dementia or worse, 35.9%; moderate AD dementia to severe AD dementia, 28.6%. Transition probabilities to less severe dementia stages were: 5.3% annual reversion from MCI-AD to asymptomatic, 3.0% mild AD dementia to MCI-AD, 1.8% moderate AD dementia to mild AD dementia, and 1.3% for severe AD dementia to moderate AD dementia. CONCLUSIONS: These transition probabilities reflect the full continuum of AD progression in Aβ+ individuals and can be used to assess the impact of treatment on expected transitions. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40120-021-00272-1.