Erika J Laukka1, Stuart W S MacDonald, Lars Bäckman. 1. Aging Research Center, Karolinska Institutet and Stockholm Gerontology Research Center, Stockholm, Sweden. Erika.Jonsson.Laukka@ki.se
Abstract
OBJECTIVE: In a previous study, the authors found no accelerated decline in close proximity to death for a measure of global cognitive functioning, after excluding persons in a preclinical phase of dementia. However, specific cognitive tasks might be more sensitive to terminal-decline effects. The purpose of this study was to explore possible terminal-decline effects for a range of cognitive tasks after controlling for preclinical dementia. DESIGN: Community-based cohort study. SETTING: The Kungsholmen district of Stockholm. PARTICIPANTS: A total of 585 persons (75+ years) were repeatedly assessed over an 11-year period. Level and change in cognitive performance were compared for three groups: persons in close proximity to death, persons in a preclinical phase of dementia, and persons who remained alive and nondemented throughout the study. MEASUREMENTS: Tasks assessing primary and episodic memory, verbal ability, and visuospatial skill. RESULTS: Compared with an analysis where all dead subjects were included in the impending-death group, removing the preclinical dementia cases resulted in markedly attenuated mortality-related effects. However, the impending-death group still declined at a faster rate relative to the comparison group on Digit Span-forward, word recognition, and category fluency. Notably, these were tasks for which the comparison group showed no significant decline. CONCLUSIONS: A considerable proportion of the terminal-decline effect is accounted for by the impact of preclinical dementia. However, for tasks that are relatively resistant to age-related change, such effects might be detected independently of preclinical dementia.
OBJECTIVE: In a previous study, the authors found no accelerated decline in close proximity to death for a measure of global cognitive functioning, after excluding persons in a preclinical phase of dementia. However, specific cognitive tasks might be more sensitive to terminal-decline effects. The purpose of this study was to explore possible terminal-decline effects for a range of cognitive tasks after controlling for preclinical dementia. DESIGN: Community-based cohort study. SETTING: The Kungsholmen district of Stockholm. PARTICIPANTS: A total of 585 persons (75+ years) were repeatedly assessed over an 11-year period. Level and change in cognitive performance were compared for three groups: persons in close proximity to death, persons in a preclinical phase of dementia, and persons who remained alive and nondemented throughout the study. MEASUREMENTS: Tasks assessing primary and episodic memory, verbal ability, and visuospatial skill. RESULTS: Compared with an analysis where all dead subjects were included in the impending-death group, removing the preclinical dementia cases resulted in markedly attenuated mortality-related effects. However, the impending-death group still declined at a faster rate relative to the comparison group on Digit Span-forward, word recognition, and category fluency. Notably, these were tasks for which the comparison group showed no significant decline. CONCLUSIONS: A considerable proportion of the terminal-decline effect is accounted for by the impact of preclinical dementia. However, for tasks that are relatively resistant to age-related change, such effects might be detected independently of preclinical dementia.
Authors: Andrea M Piccinin; Graciela Muniz; Catharine Sparks; Daniel E Bontempo Journal: J Gerontol B Psychol Sci Soc Sci Date: 2011-07 Impact factor: 4.077
Authors: Andrea M Piccinin; Graciela Muniz; Fiona E Matthews; Boo Johansson Journal: J Gerontol B Psychol Sci Soc Sci Date: 2011-03-09 Impact factor: 4.077