Comparing two methods to quantify physical resilience.

Physical resilience, conceptualized as the extent of observed recovery after a health stressor, is an important construct in research on aging and frailty. Various methods have been proposed to quantify physical resilience using repeated measures of health or function following a stressor. The purpose of this analysis is to directly compare two alternative approaches to quantifying physical resilience - the recovery trajectory (RT) and the expected recovery differential (ERD) - using data from 170 older adults in an observational study of elective knee replacement surgery. Each participant's resilience, based on repeated measures of pain interference over 6 months after surgery, was determined using both the RT and the ERD method. The 10 individuals classified as high resilience based on RT also had better-than-expected recovery based on ERD. However, ERD scores were more variable among individuals classified by RT as moderate resilience (n = 82). Of those classified as low resilience (n = 78) by RT, most (85.9%) also had worse-than-expected recovery based on ERD. In this head-to-head comparison of two conceptually distinct approaches for quantifying resilience after a health stressor, the results were most comparable in individuals at extremes of high or low recovery patterns. Each approach has merit for quantifying physical resilience after a health stressor, and factors that may influence the choice of method and interpretation of results are discussed.

Duke Scholars

Author Heather Elizabeth Whitson Medicine, Geriatrics and Palliative Care

Author Cathleen Sellner Colon-Emeric Medicine, Geriatrics and Palliative Care

Author Katherine Shepherd Hall Medicine, Geriatrics and Palliative Care

Author Virginia Byers Kraus Medicine, Rheumatology and Immunology