Frailty and long-term outcomes following critical illness: A population-level cohort study

Purpose To provide population-level estimates of the association of frailty with one-year outcomes after critical illness. Materials and methods Retrospective cohort study of patients who survived an ICU admission between April 2002 and March 2015. Pre-existing frailty was classified using the Johns Hopkins Adjusted Clinical Groups frailty indicator. Multivariable Cox regression and Fine and Gray models were used to examine the association between frailty and mortality and hospital readmission. Results Of 534,991 patients, 19.3% had pre-existing frailty. Compared to non-frail survivors, at one-year frail patients had higher mortality (18.3% vs 9.5%, adjusted HR 1.17 95% CI: 1.15–1.19) and hospital readmission (44.4% vs 36.6%, adjusted HR 1.10 95% CI: 1.08–1.11) and a CAN$19,628 (95% CI: $19,279–$19,997) greater increase in healthcare costs compared to the year prior to hospitalization. The association between frailty and mortality was stronger among older individuals, but the risk of readmission among frail patients decreased with age. Conclusion Patients with pre-existing frailty who develop critical illness have higher rates of hospital readmission and death than patients without frailty, and age modifies these associations. These data highlight the importance of considering both frailty and age when seeking to identify at-risk patients who might benefit from closer follow-up after discharge.