Outcomes relevant to patients and care partners along the trajectory of Alzheimer’s disease
Authors:   , Mank Arenda 
Published: June 2024

In chapter 2, we identified the most relevant outcomes from the viewpoints of patients and care partners. We used a two-step, mixed methods approach. As a first step we conducted four focus groups in Dutch patients and their care partners to develop a comprehensive list of outcomes considered important by patients and care partners in the prognosis of AD. This resulted in one core outcome list, comprising 13 items. Both patients and care partners selected outcomes from the category “cognition” most often, followed by the categories “functioning and dependency” and “physical health”. The list with outcomes of relevance to patients and care partners was then used to inform subsequent studies on Patient Reported Outcomes (PROs) along the trajectory of AD.

In chapter 3, we developed and validated models to predict institutionalization and mortality along the AD continuum of Subjective Cognitive Decline (SCD), Mild Cognitive Impairment (MCI) and AD dementia. In SCD/MCI and dementia stages, the models predicting future institutionalization and mortality included clinical characteristics, imaging and cerebrospinal fluid (CSF) biomarkers after backward selection. Discriminative performance was better in SCD/MCI patients than in patients with AD dementia. Models based on data from amyloid-positive patients, had similar discrimination. The developed prediction models can be used to provide patients and their care partners with prognostic information on time to institutionalization and mortality along the cognitive continuum of AD.

In chapter 4, we compared the Quality of Life (QoL) trajectories of amyloid-positive and amyloid-negative SCD and MCI patients and we evaluated QoL trajectories along the AD continuum of SCD, MCI and AD dementia. We showed that QoL decreased at a faster rate over time in amyloid-positive SCD or MCI patients than in amyloid-negative patients. In addition, when we evaluated the full continuum of AD, QoL decreased at a faster rate in patients with amyloid-positive patients with
AD dementia compared to amyloid-positive SCD or MCI. Knowledge of QoL trajectories along the full trajectory of AD is essential for the evaluation of the effect of (future) treatments on the QoL of AD patients.

In chapter 5, we focused on a positive outcome, as we studied life satisfaction across AD stages, evaluating transportation and meaningful activities as mediators of the associations between these AD stages and life satisfaction in single and multiple mediator models. We found that patients with dementia are less satisfied with life compared to SCD and MCI. These differences in life satisfaction are explained by reduced participation in meaningful activities, which in turn, was largely attributable to decreased use of transportation. Our findings suggest that improving access to transportation.

In chapter 7, we studied care partner outcomes and evaluated patient and care partner determinants associated with care partner outcomes in care partners of amyloid-positive patients with SCD, MCI and AD dementia. The outcomes were informal care time, caregiver distress, depression and QoL. We found that both patient and care partner determinants contribute to the care partner outcomes. Care partners spent more time on care when patients had more behavioral symptoms and functional impairment. More behavioral symptoms were related with more caregiver distress. Spouse care partners spent more time on informal care and QoL was lower in female care partners. Behavioral problems and subtle functional impairment of the patient were associated with worse care partner outcomes already in the pre-dementia stages. These results help to identify care partners at risk of high burden. These results demonstrate that it is important that researchers and health care professionals do not only focus on outcomes related
to patients, but also on the care partner outcomes, even in the pre-dementia stages.