Epidemiology of restricting fatigue in older adults: the precipitating events project

Objectives: To estimate the rate of restricting fatigue in community-living older adults and to determine whether the rates differ according to age, sex, race, physical frailty, and depression.

Design: Prospective cohort study.

Setting: Greater New Haven, Connecticut.

Participants: Nondisabled community-living older men and women aged 70 and older (N = 754).

Measurements: Restricting fatigue was defined as staying in bed for at least half the day and/or cutting down on one's usual activities because of fatigue for 3 consecutive months or longer. Physical frailty was defined on the basis of slow gait speed, and depression was assessed using the Center for Epidemiologic Studies Depression Scale.

Results: During a median follow-up of 111 months, the cumulative incidence of restricting fatigue was 31.1% for men and 42.1% for women. The overall incidence rate of restricting fatigue was 6.7 per 1,000 person-months (7.8 for women and 4.4 for men, P < .001), which did not differ according to race. Rates were higher in persons who were physically frail than those who were not (P < .001), in those who were depressed than those who were not (P < .001), and in persons aged 75 to 79 and 80 to 84 than those aged 70 to 74 (both P < .01) but not in those aged 85 and older. Of the 459 episodes of restricting fatigue, the median duration was 3 months, which did not differ according to age, sex, race, physical frailty, or depression.

Conclusion: Restricting fatigue is common in community-living older adults. Women, individuals aged 75 to 84, and individuals with physical frailty or depression had higher rates of restricting fatigue than their respective counterparts.