Does Personal Assistance Substitute for Mobility Devices: A Simultaneous Equations Approach

Personal assistance (human help) and mobility devices (cane, walker, wheelchair, and scooters) are important in facilitating community living and maintain quality of life in later life. Evidence regarding whether personal assistance can substitute for mobility devices is unclear. The objective of this study was to examine whether personal assistance substitute for the use of mobility devices for U.S. community-living older adults with mobility difficulties. We used the 2011 wave of the National Health and Aging Trend Study (NHATS) data. Two primary outcomes variables were: any use of mobility device and any use of personal assistance during the month before the baseline interview. We used a recursive simultaneous equations model to jointly estimate the effect of covariates on the likelihood of using various combinations of mobility devices and personal assistance to accommodate mobility difficulty. Independent variables included age, gender, race, physical/mental health status, cognition, comorbidities, and mobility difficulty. The average age of the study sample was 78 years and 58% were female. Multivariate analysis found that predictors of personal assistance and mobility devices exhibit important similarities and differences. Receiving personal assistance reduced the likelihood of using mobility device by 53% (OR=0.47, 95% CI: 0.33, 0.66). Women were much less likely to use mobility devices but were much more likely to use personal assistance. The findings suggest that personal assistance substitutes for mobility devices and important gender differences exist in the substitution. Further research is needed to examine the optimal combination of different accommodation approaches in promoting positive aging in the community.