Long-term frailty trajectory in older ICU survivors requiring mechanical ventilation: a prospective cohort study in...

While intensive care unit (ICU) capacity remains constrained, the number of older patients receiving resource-demanding ICU treatment continues to rise. Yet, long-term outcomes and post-critical illness frailty trajectories remain poorly characterized. We examined long-term mortality and frailty trajectories, and their associations with clinical characteristics and ICU treatment intensity.

In this prospective, observational study across five Norwegian hospitals representing all health regions, we included patients aged ≥65 years who required invasive mechanical ventilation for ≥24 h. Frailty was assessed using the Clinical Frailty Scale (CFS) at baseline and at 3 and 12 months, categorized as robust (CFS 1-3), prefrail (CFS 4) and frail (CFS ≥ 5). Multiple regression models were used to examine associations between frailty trajectories and mortality, with baseline frailty, clinical characteristics and potentially modifiable aspects of ICU treatment.

346 patients were included. Mean age was 74 years (± 6), and 98 % lived at home before admission. The median ICU length of stay was 8 (IQR 9) days. Total mortality was 52 %, with most deaths occurring before hospital discharge. In the survivors, the prevalence of frailty increased from 23 % (79/346) at baseline, to 47 % (81/174) at three months. Between the three- and 12- month follow-up, CFS scores remained unchanged in 71 % (108/153), improved in 19 % (29/153) and deteriorated in 10 % (15/153). By 12 months 86 % (132/153) had returned home, though 32 % (49/153) required home care compared to 10 % pre-admission. Baseline CFS showed the strongest association with 12-month mortality (Risk Ratio 1.46, p < 0.001). Age (Risk Ratio 1.22, p < 0.001) and SOFA score on the first day after intubation (Risk Ratio 1.14, p < 0.01) were also significant predictors, whereas comorbidity was not.

In elderly ICU-patients long-term frailty is deranged, and baseline CFS is closely associated with mortality. However, a small group of patients had a transitory decline in frailty at three months follow-up and then improved. Intervention studies targeting modifiable factors associated with long-term functional decline and mortality are warranted.

ClinicalTrials.gov (NCT06012942).