Comparison of Self-Reported and Capacity-Based Measures of Mobility in Community-Dwelling Older Adults in Nigeria: The Mediating Role of Age, Cognitive Status, and Chronic Conditions.

Background and Objectives: Although the association between self-reported and capacity-based mobility outcomes is prominently researched, the pathways through which self-reported measures affect capacity-based measures remains poorly understood. Therefore, our study examines the association between self-reported and capacity-based mobility measures and explores which mobility determinants mediate the association in Nigerian community-dwelling older adults. Research Design and Methods: This cross-sectional study included 169 older adults [mean age (SD) = 67.7 (7.0)]. Capacity-based mobility outcomes included the Short Physical Performance Battery (SPPB), the 6-Minute Walk Test (6MWT), and the 10-Meter Walk Test (10mWT), whereas the self-reported mobility outcomes included the Lower Extremity Functional scale (LEFS), the Life Space Questionnaire (LSQ), and the Mänty Preclinical Mobility scale (inability to walk 2 km, 0.5 km, or climb a flight of stairs). Spearman's correlations were conducted to examine the relationship between self-reported and capacity-based mobility measures, whereas structural equation modeling was used to determine the mediators. Results: The correlation between SPPB and LEFS (rho = 0.284) and 0.5 km (rho = -0.251) were fair, whereas the correlation between SPPB and inability to walk 2 km (rho = -0.244) and inability to climb a flight of stairs (rho = -0.190) were poor. Similarly, correlations between 6MWT and the LEFS (rho = 0.286), inability to walk 2 km (rho = -0.269), and 0.5 km (rho = -0.303) were fair. The 6WMT was poorly correlated with inability to climb one flight of stairs (rho = -0.233). The LSQ was not correlated with SPPB or 10mWT. Age was the only significant mediator, whereas the number of chronic conditions and cognitive status were not. Discussion and Implications: The correlation between self-reported and capacity-based mobility outcomes in older adults in Nigeria is lower than those in developed countries. Our analysis provides a foundation to explore mobility determinants that could be predictive mediators for mobility outcomes, making meaningful contributions to explaining mobility complexities.