Background: Diagnostic tests, such as amyloid-β positron emission tomography (PET) scans, can increase appropriate therapeutic management for the underlying causes of cognitive decline. To evaluate the full utility of this diagnostic tool, information is needed on whether results from amyloid-β PET scans influence care-partner outcomes.
Objective: This study examines the extent to which previous disclosure of elevated amyloid (suggestive of Alzheimer's disease (AD) etiology) versus not-elevated amyloid (not suggestive of AD etiology) is associated with changes in care-partner wellbeing.
Methods: The study used data derived from a national longitudinal survey of Medicare beneficiaries (n = 921) with mild cognitive impairment (MCI) or dementia and their care-partners. Care-partner wellbeing outcomes included depressive symptoms (PHQ-8), subjective burden (4-item Zarit burden score), and a 3-item measure of loneliness. Change was measured between 4 (Time 1) and 18 (Time 2) months after receiving the scan results. Adjusted linear regression models regressed change (Time 2-Time 1) in each outcome on scan result.
Results: Care-partners were primarily white, non-Hispanic, college-educated, and married to the care recipient. Elevated amyloid was not associated with statistically significant Time 1 differences in outcomes or with statistically significant changes in depressive symptoms 0.22 (-0.18, 0.61), subjective burden 0.36 (-0.01, 0.73), or loneliness 0.15 (-0.01, 0.32) for care-partners from one time point to another.
Conclusion: Given advances in AD biomarker testing, future research in more diverse samples is needed to understand the influence of scan results on care-partner wellbeing across populations.
Keywords: Amyloid-β; caregiver; dementia; depression; mild cognitive impairment; positron emission tomography.