HOME HELP FEEDBACK SUBSCRIPTIONS ALL ISSUES SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a Colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by Laukka, E. J. Articles by Bäckman, L. PubMed PubMed Citation Articles by Laukka, E. J. Articles by Bäckman, L.

Terminal-Decline Effects for Select Cognitive Tasks after Controlling for Preclinical Dementia

From the Aging Research Center, Karolinska Institutet and Stockholm Gerontology Research Center, Stockholm.

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.

Key Words: Aging • cognition • longitudinal studies • preclinical dementia • impending death

This article has been cited by other articles:

				M. Ganguli and R. C. Petersen Mild Cognitive Impairment: Challenging Issues Am J Geriatr Psychiatry, May 1, 2008; 16(5): 339 - 342. [Full Text] [PDF]