Recovery after critical illness in patients aged 80 years or older: a multi-center prospective observational cohort study

Purpose: Increasingly, very old patients are admitted to Intensive Care Units (ICUs). The objective of this study was to describe 12-month outcomes of these patients and determine which characteristics are associated with a return to baseline physical function 1 year later. Methods: In this prospective cohort study in 22 Canadian hospitals, we recruited 610 patients aged 80 years or older who were admitted to ICU for at least 24 h. At baseline, we completed a comprehensive geriatric assessment and followed patients to determine 12-month survival and physical function. Our primary outcome was physical recovery from critical illness at 12 months, defined as being alive with Short Form-36 physical function score of at least 10 points, and not 10 or more points below baseline. We used regression analysis to examine factors associated with physical recovery. Results: Patients were on average 84 years old (range 80-99). Mortality was 14 % in ICU, 26 % in hospital and 44 % at 12 months after admission. Of 505 patients evaluable at 12 months, 26 % achieved physical recovery. In the multivariable model, physical recovery was significantly associated with younger age, lower APACHE II score, lower Charlson comorbidity score, lower frailty index, lower baseline physical function score, and specific admission diagnoses. Conclusions: One-quarter of patients aged 80 years or older who are admitted to ICU survived and returned to baseline levels of physical function at 1 year. Routine assessment of baseline physical function and frailty status could aid in prognostication and informed decision-making for very old critically ill patients.