A prolonged intensive care unit stay defines a worse long-term prognosis - Insights from the critically ill mortality by age (Cimba) study.

Background: Patients with critical illness often survive the intensive care unit (ICU) at a cost of prolonged length of stay (LOS) and slow recovery. This chronic critically ill disease may lead to long-term poor outcomes, especially in older or frail patients.

Objectives: The main goal of this study was to address the characteristics and outcomes of patients with prolonged ICU LOS. Mainly, short- and long-term admissions were compared to identify risk factors for persistent critical illness and to characterise the impact on ICU, hospital, and long-term mortality.

Methods: Subanalysis of a retrospective, multicentric, observational study addressing the 2-year outcome of patients admitted to Portuguese ICUs (the Cimba study). Patients were segregated according to an ICU LOS of ≥14 days.

Results: Data from 37 118 patients were analysed, featuring a median ICU LOS of 4 days (percentile: 25-75 2-9), and a mortality of 16.1% in the ICU, 24.0% in the hospital, and 38.7% after 2 years. A total of 5334 patients (14.4%) had an ICU LOS of ≥14 days (corresponding to 48.9% of all ICU patients/days). Patients with prolonged LOS were more often younger (52.8% vs 46.4%, were ≤65 years of age , p < 0.001), although more severe (Simplified Acute Physiology Score II: 49.1 ± 16.9 vs 41.8 ± 19.5, p < 0.001), and had higher ICU and hospital mortality (18.3% vs 15.7%, and 31.2 vs 22.8%, respectively). Prolonged ICU LOS was linked to an increased risk of dying during the 2-year follow-up (adjusted Cox proportional hazard: 1.65, p < 0.001).

Conclusion: Prolonged LOS is associated with a long-term impact on patient prognosis. More careful planning of care should incorporate these data.