Association Between Life Space and Risk of Mortality in Advanced Age

OBJECTIVES To examine the association between life space, a measure of functional status that describes the range of movement through the environment covered during daily functioning, and the risk of mortality in older community-based persons. DESIGN Two ongoing, prospective observational cohort studies of aging. SETTING Greater metropolitan Chicago area. PARTICIPANTS One thousand four hundred forty-five community-based older persons without dementia. MEASUREMENTS Life space was measured at baseline using a series of questions designed to measure the extent of participants' movement throughout their environment, ranging from the bedroom to out of town. The association between life space and mortality was examined using proportional hazards models adjusted for age, sex, race, and education. RESULTS Over up to 8 years of follow-up (mean 4.1 years), 329 of 1,445 (22.8%) participants died. In a proportional hazards model adjusted for age, sex, race, and education, a more-constricted life space was associated with a greater risk of death (hazard ratio=1.18, 95% confidence interval=1.09-1.27, P <.001), such that people with life spaces constricted to their immediate home environment (score=3) were approximately 1.6 times as likely to die as those whose life spaces included trips out of town (score=0). This association persisted after the addition of terms for several potential confounders, including physical activity, performance-based physical function, disability, depressive symptoms, social networks, body mass index, and number of chronic medical conditions. CONCLUSION Constricted life space is associated with greater risk of death in older community-based persons.