Fatigue, function, and mortality in older adults

Abstract

Background: Although fatigue is common among the elderly people, little is known concerning its relationship with mortality and function over extended periods of time among the very old. This study evaluates the association of fatigue with health, functional status, and mortality from ages 70-88 years.

Methods: Mortality data from ages 70-88 years and both health and functional status at age 70, 78, and 85 years were assessed among a representative community-dwelling cohort born 1920-1921 from the Jerusalem Longitudinal Study (1990-2008).

Results: At age 70, 78, and 85, fatigue prevalence was 29%, 53%, and 68%, respectively, with increased prevalence among women. Fatigue was associated with poorer health, function, and psychosocial parameters at all ages and greater likelihood to deteriorate in subsequent self-rated health (SRH), functional status, loneliness, depression, and physical activity level. After adjustment, fatigue at age 70 predicted poor subsequent SRH, difficulty in activities of daily living, reduced levels of physical activity, and poor sleep satisfaction, and at age 78, fatigue predicted subsequent depression. Hazard ratios for mortality among fatigued participants were significant after adjustment for numerous risk factors. The addition of physical activity level and/or depression reduced the significance of the relationship between fatigue and mortality.

Conclusions: Fatigue among the elderly people, up to and including the oldest old, has a significant negative impact on health status, function, and mortality. Pathways of action may be related to the complex relationship of fatigue with depression and levels of physical activity.