Measuring Alzheimer's disease progression with transition probabilities in the Taiwanese population

Background. The transition probability of Alzheimer's disease (AD) is defined as the likelihood that the disease progresses from one stage to another in a given time period. Objective. To estimate the separate stage-to-stage and stage-to-death transition probabilities for Taiwanese patients with AD and to evaluate the hazard ratios of age, sex, behavioral symptoms, and medications on disease progression. Method. We examined data (severity of dementia, hallucinations or delusions, use of cholinesterase inhibitors [CEIs], survival) in 365 patients with probable AD at baseline and at follow-up (mean ± SD 29 ± 17 months, range 3-109 months). Results. Modified survival analysis revealed that transition probabilities of Taiwanese patients were similar to those of Western patients. The probability of dementia remaining at the same stage was higher in patients taking CEIs than in other. Men had a higher probability of dying in the mild stage. Conclusion. Transition probabilities can be used to measure AD progression. CEIs used to treat AD might alter the disease course.