Predictors of Physical Resilience in Older Adults

Physical resilience (PR), which denotes one’s ability to resist functional physical decline, can be operationalized through longitudinal assessments on the Short Physical Performance Battery (SPPB). Dual-task walking (DTW) is predictive of adverse outcomes but its role in predicting incident PR has not been assessed. Herein, we determined whether velocity during Single-Task-Walk (STW) and Dual-Task-Walk (DTW) conditions predicted incident loss of PR and identified moderators of this relationship. Participants were 163 (mean age=75.5; %female=52) non-demented, community-dwelling older adults with baseline SPPB scores of 10-12. At baseline, individuals completed neuropsychological testing, the SPPB and DTW paradigm. Cognitive reserve was evaluated using the Wide Range Achievement Test (WRAT-3) and speed of processing was assessed using the Symbol Digit Modalities Test (SDMT). Individuals with SPPB scores < 10 were categorized as not physically resilient. Those with scores of 10 or higher were categorized as physically resilient. At three-year follow up 75.4% (n=123) of participants remained physically resilient while 24.5% (n=40) lost PR. Binary logistic regression revealed that slower DTW (OR= 0.96, p= 0.033, 95%CI [.926, .997]), but not STW velocity (OR= 1.00, p= 0.861, 95%CI [0.962, 1.048]), was a significant predictor of PR loss. Moreover, moderation analyses revealed that DTW velocity predicted PR loss only among individuals who had lower baseline scores on the WRAT-3 (OR=0.937, p=0.004, 95%CI [.896, .979]) and SDMT (OR=0.949, p=0.018, 95%CI [.909, .991]). We propose that cognitive reserve and speed of processing influenced the utility of DTW velocity in predicting PR loss among community-residing older adults.