Longitudinal Fatigue Trajectories and Outcomes Among <scp>ICU</scp> Survivors: A Multicentre Prospective Cohort Study

BACKGROUND: Fatigue is highly prevalent among ICU survivors and is associated with adverse outcomes. However, its longitudinal trajectories and prognostic significance remain unclear. AIM: To identify fatigue trajectories after critical illness, determine baseline predictors and examine their associations with long-term mortality and health-related quality of life (HRQoL). STUDY DESIGN: This prospective multicentre cohort study was conducted in 10 ICUs across five tertiary hospitals in Fujian Province, China, from February 2022 to August 2023. Fatigue was assessed using the 14-item Fatigue Scale (FS-14) at ICU admission, ICU discharge, hospital discharge and 1 week, 2 weeks, 1 month and 6 months after discharge. The primary outcome was the 6-month fatigue trajectory group, identified using group-based trajectory modelling. Secondary outcomes were 6- and 12-month mortality and 6-month HRQoL. Multinomial logistic regression was used to examine baseline predictors of fatigue trajectory group. Inverse probability treatment weighting-adjusted Cox models were used for mortality, and weighted linear regression models were used for HRQoL. RESULTS: Among 348 critically ill adults, three fatigue trajectories were identified: persistent fatigue (38.8%), recovered fatigue (43.1%) and no fatigue (18.1%). Recovered fatigue was associated with older age, prolonged mechanical ventilation, lower skeletal muscle index and higher Hospital Anxiety and Depression Scale scores. Compared with no fatigue, persistent fatigue was associated with lower physical HRQoL at 6 months (estimate -13.17, 95% CI: -19.85 to -6.495, p < 0.001), and higher 12-month mortality (hazard ratio, 6.75; 95% CI, 1.37-33.35; p = 0.019). CONCLUSIONS: Fatigue trajectories after critical illness are heterogeneous. Persistent fatigue is linked to modifiable clinical factors and is associated with impaired HRQoL and increased long-term mortality. RELEVANCE TO CLINICAL PRACTICE: Routine fatigue assessment should be embedded in ICU care to identify patients at risk for persistent fatigue, enabling personalised rehabilitation and self-management strategies that reduce symptom burden and promote long-term recovery.