Life-Space Mobility and Cognitive Decline Among Mexican Americans Aged 75 Years and Older

Abstract

Objectives: To examine the association between life-space mobility and cognitive decline over a five-year period among older Mexican Americans.

Design: Longitudinal study.

Setting: Hispanic Established Population for the Epidemiologic Study of the Elderly survey conducted in the southwestern of United States (Texas, Colorado, Arizona, New Mexico, and California).

Participants: Four hundred thirty-two Mexican Americans aged 75 and older with normal or high cognitive function at baseline.

Measurements: Socio-demographic factors, living arrangement, type of household, social support, financial strain, self-reported medical conditions, Mini-Mental State Examination (MMSE), depressive symptoms, activities of daily living (ADLs), and Short Physical Performance Battery. Life-space assessment (LSA) during the past 4 weeks was assessed during in-home interview. Scores ranged from 0 (daily restriction to the bedroom) to 120 (daily trips outside of their own town without assistance) and categorized as 0 to 20, 21 to 40, 41 to 60, 61 to 80, and 81 to 120. Because of the small sample size in the category of 81 to 120, the two highest categories were combined into a single group.

Results: The mean LSA score and MMSE score of participants at baseline was 44.6 (Standard Deviation [SD], 20.7) and 25.7 (SD, 3.2), respectively. Mixed Model analyses showed that participants in the highest life-space category (≥61) experienced slower rates of cognitive decline over time compared to participants in the lowest category (0 to 20) (β = 1.03, Standard Error [SE] = 0.29, P = 0.0004), after adjusting for all covariates.

Conclusion: Greater life-space mobility at baseline was predictor of slower rates of cognitive decline over 5 years in older Mexican Americans.

Keywords: Mexican Americans; cognition; life-space; mobility; older adults.