Frailty, Acute Brain Dysfunction, and Posthospitalization Disability Outcomes in Critically Ill Older Adults

Abstract

Background Identifying potentially modifiable factors that mediate adverse outcomes in frail adults with critical illness may facilitate development of interventions to improve intensive care unit (ICU) survivorship. Objectives To estimate the relationship between frailty, acute brain dysfunction (as reflected by delirium or persistent coma), and 6-month disability outcomes. Methods Older adults (aged ≥50 years) admitted to the ICU were enrolled prospectively. Frailty was identified with the Clinical Frailty Scale. Delirium and coma were assessed daily with the Confusion Assessment Method for the ICU and the Richmond Agitation-Sedation Scale, respectively. Disability outcomes (death and severe physical disability [defined as new dependence in 5 or more activities of daily living]) were assessed by telephone within 6 months after discharge. Results In 302 older adults (mean [SD] age, 67.2 [10.8] y), both frail and vulnerable patients had a higher risk for acute brain dysfunction (adjusted odds ratio [AOR], 2.9 [95% CI, 1.5-5.6], and 2.0 [95% CI, 1.0-4.1], respectively) compared with fit patients. Both frailty and acute brain dysfunction were independently associated with death or severe disability at 6 months (AOR, 3.3 [95% CI, 1.6-6.5] and 2.4 [95% CI, 1.4 -4.0], respectively). The average proportion of the frailty effect mediated by acute brain dysfunction was estimated to be 12.6% (95% CI, 2.1%-23.1%; P = .02). Conclusion Frailty and acute brain dysfunction were important independent predictors of disability outcomes in older adults with critical illness. Acute brain dysfunction may be an important mediator of increased risk for physical disability outcomes after critical illness.