Frequency of cognitive “super-aging” in three Australian samples using different diagnostic criteria

Abstract

Objectives: To investigate the frequency of exceptional cognition (cognitive super-aging) in Australian older adults using different published definitions, agreement between definitions, and the relationship of super-aging status with function, brain imaging markers, and incident dementia. Design: Three longitudinal cohort studies. Setting: Participants recruited from the electoral roll, Australian Twins Registry, and community advertisements. Participants: Older adults (aged 65–106) without dementia from the Sydney Memory and Ageing Study (n = 1037; median age 78), Older Australian Twins Study (n = 361; median age 68), and Sydney Centenarian Study (n = 217; median age 97). Measurements: Frequency of super-aging was assessed using nine super-aging definitions based on performance on neuropsychological testing. Levels of agreement between definitions were calculated, and associations between super-aging status for each definition and functioning (Bayer ADL score), structural brain imaging measures, and incident dementia were explored. Results: Frequency of super-aging varied between 2.9 and 43.4 percent with more stringent definitions associated with lower frequency. Agreement between different criteria varied from poor (K = 0.04, AC1 = .24) to very good (K = 0.83, AC1 = .91) with better agreement between definitions using similar tests and cutoffs. Super-aging was associated with better functional performance (4.7–11%) and lower rates of incident dementia (hazard ratios 0.08–0.48) for most definitions. Super-aging status was associated with a lower burden of white matter hyperintensities (3.8–33.2%) for all definitions. Conclusions: The frequency of super-aging is strongly affected by the demographic and neuropsychological testing parameters used. Greater consistency in defining super-aging would enable better characterization of this exceptional minority.

What underlies exceptional memory function in older age? No evidence for aging-specific relationships to hippocampal atrophy and retrieval activity

“…First, we followed the most common approach used in previous research on SuperAgers, which is to classify high-performing older adults as participants above 60 years with memory scores above the average of the participants in the age-range 20 to 60 years (Powell, Page, Close, Sachdev, & Brodaty, 2023). Note that there is no uniform definition of SuperAgers, and a review reported that frequency of SuperAgers varies from 2.9% to 43.4% as a function of differences in definition (Powell, Lam, et al, 2023). It has been argued that a start age of 60 years, rather than 80 years, which was used in the original work on SuperAgers (Harrison et al, 2012), is problematic when the aim is to make meaningful statements about resilience and resistance to age-decline (Rogalski, 2019).…”

“…Some older adults show superior memory function compared to same-age peers, and even perform on par with much younger persons (Powell, Lam, et al, 2023). These very high-performing older adults are sometimes referred to as SuperAgers (Harrison, Weintraub, Mesulam, & Rogalski, 2012).…”