Abstract 18: Discrepancies Between the Adaptive Strategies Used for Mobility Tasks and Measured Physical Performance

Abstract

Objective: To describe the relationship between adaptive strategies for in-home mobility and lower-extremity physical performance. Design: Cross-sectional study. Setting: Community-dwelling elders. Participants: Age-stratified random sample of the one third most disabled cognitively intact women aged 65 or older in Baltimore, MD (N=1002). Interventions: Not applicable. Main Outcome Measures: Gait speed, timed chair stands, balance, and a 4-level ranked mutually exclusive measure of adaptive strategy summarizing use of 3 adaptive methods for in-home mobility: behavioral modifications (BM), durable medical equipment (DME), and human help (HH). The least intensive level was no modifications (BM-DME-HH-), followed by behavior only (BM+DME-HH-), then equipment (BM+/-DME+HH-), and finally human help (BM+/-DME+/-HH+). Results: The adaptive strategy scale demonstrated Guttman scalability (coefficient of reproducibility, .96). The correlation coefficient of adaptive strategy was −.52 for gait speed, −.47 for chair stands per second, and −.41 for balance. Cumulative histograms for each performance measure consistently showed the worst performance in the equipment group, followed by human help, then behavior, and finally no modifications. Kruskal-Wallis and Wilcoxon rank-sum tests demonstrated the differences in physical performance for the various adaptive strategy levels were statistically significant. Multivariate, orthogonal, logistic regression models identified additional statistically significant predictors of adaptive strategy, which varied by type of adaptive strategy. Conclusions: Physical performance correlated with the adaptive strategy used for mobility. The traditional hierarchical adaptive strategy scale met Guttman scalability criteria. However, users of equipment but no human help actually exhibited worse measured physical performance than those using human help for mobility tasks. Other statistically significant factors varied according to the adaptive strategy. These factors may explain the discrepancy between the traditional hierarchical scale, anchored with human help as most severe, and measured physical abilities, which were most impaired for women using equipment but no human help.