Subjective Beliefs, Memory and Functional Health: Change and Associations over 12 Years in the Australian Longitudinal Study of Ageing

Abstract

Background: Neither subjective memory beliefs, nor remembering itself, can be isolated from the overall context in which one is aging, nor are the drivers of memory complaints well specified. Sense of control is an important self-regulatory resource that drives cognitive and physical health over the lifespan. Existing findings are equivocal concerning both the extent of stability or change in control beliefs over time as well as their contribution to changes in behavior. Objective: Subjective beliefs may play a role when engaging memory processes or identifying memory complaints, and it has been argued that self-regulatory potential in general may be limited by age-related changes in the domains of health and cognition. We aimed to examine trajectories of change and shed light on relationships among subjective beliefs and indicators of memory and functional health. Methods: Participants' data were drawn from four measurement occasions over up to a 12-year period (1992-2004) from the Australian Longitudinal Study of Ageing (ALSA), a population-based study of older adults [age 65-100 years; mean age(SD) at the first and final occasion 78.2 (6.7) and 84.9 (4.9) years, respectively]. Participants completed three questionnaires assessing subjective beliefs concerning (1) memory knowledge and control, (2) health control, and (3) expectancy of control over a range of lifestyle situations. Memory comprised a recall composite. Functional health tapped mobility and disability. Latent growth curve models incorporated informative covariates (baseline age, gender, self-rated health, education, and chronic conditions). Results: While subjective memory control beliefs, but not subjective knowledge of memory tasks, improved over 12 years, neither was associated with level of memory performance. Knowledge of memory tasks was linked to a significant memory decline. Beliefs about memory, health, and lifestyle were interrelated. Declines in remembering and health were also coupled; moreover, changes in both were coupled with change in lifestyle control beliefs. Conclusions: This is the first examination of individual differences in changes in, and relationships among, psychological domains of subjective beliefs about memory, health, and lifestyle, and objective remembering and functional health in very late life. Findings point to a system of coupled changes in memory and health in late life that is related to underlying beliefs about control over lifestyle.