Predictive value of somatic and functional variables for cognitive deterioration for early-stage patients with Alzheimer's Disease: Evidence from a prospective registry on dementia.

Alzheimer's disease (AD) imposes a major burden on affected individuals, their caregivers and health-care systems alike. Though quite many risk factors for disease progression have been identified, there is a lack of prospective studies investigating the interplay and predictive value of a wide variety of patient variables associated with cognitive deterioration (defined as key feature of AD progression). Study participants were patients with probable and possible AD, that were assessed at four time points over a period of two years (T1-T4). The main results were threefold: (i) over time, significant changes were observed regarding patients' cognitive functioning, activities of daily living and caregiver load (but not depression, pain, neuropsychiatric symptoms); (ii) intercorrelations between caregiver load and patients' cognitive and functional variables were high, correlation patterns remaining rather stable across time; (iii) cognitive functioning at T4 was best predicted by patients' age, sex, atrial fibrillation and activities of daily living at T1; and (iv) across all four assessment points, cognitive functioning was best predicted by time (i.e., disease duration), age, sex, activities of daily living and depression. Overall, even in early stages of AD and during a short two-year period, functional changes were significant and tightly intertwined with caregiver load, thus stressing the need to consider caregiver load when diagnosing and treating patients with AD. A novel and clinically relevant finding is that even in early stages of AD, cognitive deterioration was best predicted by a combination of patients' demographic, somatic and functional variables.