Background: Older adults surviving critical illness often experience new or worsening functional impairments. Modifiable positive psychological constructs such as resilience may mitigate postintensive care morbidity.
Research question: Is pre-ICU resilience associated with: (1) post-ICU survival; (2) the drop in post-ICU functional independence; and (3) a lesser decline in independence before vs after the ICU?
Study design and methods: This retrospective cohort study was performed by using Medicare-linked Health and Retirement Study surveys from 2006 to 2018. Older adults aged ≥ 65 years admitted to an ICU were included. Resilience was calculated prior to ICU admission. The resilience measure was defined from the Simplified Resilience Score, which was previously adapted and validated for the Health and Retirement Study. Resilience was scored by using the Leave-Behind survey normalized to 0 (lowest resilience) to 12 (highest resilience) point scale. Outcomes were survival and probability of functional independence. Survival was modeled by using Gompertz models and independence using joint survival models adjusting for sociodemographic and clinical variables. Average marginal effects were estimated to determine independence probabilities.
Results: Across 3,409 patients ≥ 65 years old admitted to ICUs, preexisting frailty (30.5%) and cognitive impairment (24.3%) were common. Most patients were previously independent (82.7%). Mechanical ventilation occurred in 14.8% and sepsis in 43.2%. Highest vs lowest resilience had lower risk of post-ICU mortality (adjusted hazard ratio, 0.81; 95% CI, 0.70-0.94). Higher resilience was associated with greater likelihood in post-ICU independence (estimated probability of independence 5 years' post-ICU in highest-to-lowest resilience (adjusted hazard ratio [95% CI]): 0.53 (0.33-0.74), 0.47 (0.26-0.68), 0.49 (0.28-0.70), and 0.36 (0.17-0.55); P < .01. Resilience was not associated with a difference in the drop in independence across resilience groups, nor a difference in declines in independence post-ICU.
Interpretation: ICU survivors with higher resilience had increased rates of survival and functional independence, although the slope of functional decline did not differ according to resilience group pre-ICU to post-ICU.
Keywords: ICU; critical care; critical illness; psychological; recovery of function; resilience.
Published by Elsevier Inc.