Associations Between Active Mobility Index and Disability

Abstract Objectives To develop a questionnaire-based Active Mobility Index (AMI) to assess going-out behavior with physical and social activity among older adults, and to assess the criterion-related and predictive validity of the AMI. Design Prospective cohort study. Setting and Participants General community setting. Participants comprised 4432 older adults [mean age: 75.9 ± 4.3 (70-96) years; 2100 men (47.4%)]. Methods AMI assessed life-space and activities in each life-space (distance from the respondent's home: 10 km) according to physical or social activity during the past 1 month by noting frequency, purpose, type of transportation, interaction with others, and physical activity. Baseline characteristics and outcomes were compared by AMI score quartiles (highest: Q4). To examine the criterion-related validity of AMI, depressive symptoms, frailty, and cognitive function were assessed. During follow-up, incident disability was monitored by Long Term Care Insurance certification. Results Lower scores (Q1-Q3 groups) were associated with more depressive symptoms, frailty, and cognitive impairment compared with the Q4 group (all P Conclusions and Implications AMI to assess life-space with physical and social activity among older people was associated with depressive symptoms, frailty, and cognitive impairment. Lower AMI scores were associated with higher incident disability risk. Further studies are needed to elucidate whether AMI is causally associated with incident adverse health outcomes.