Frailty influences clinical outcomes in critical patients: a post hoc analysis of the PalMuSIC study.

Objective: Frailty is a multidimensional syndrome characterized by diminished physiological reserve, increasing the risk of adverse outcomes, particularly in intensive care unit patients. The Clinical Frailty Scale, ranging from 1 (nonfrail) to 9 (terminally ill), is widely used to quantify frailty. This post hoc analysis of the Palliative Multicenter Study in Intensive Care (PalMuSIC) assesses the impact of frailty and clinical severity on short- and long-term outcomes.

Methods: This subanalysis involved 23 Portuguese intensive care units and 335 patients. Patients admitted between March 1 and May 15, 2019, aged ≥ 18 years, and hospitalized for > 24 hours in the intensive care unit were eligible. The severity of illness was assessed using SAPS II, and frailty was assessed using the clinical frailty scale, which was recorded by a nurse and a doctor in charge. Patients were classified as frail (clinical frailty scale score ≥ 5), prefrail (clinical frailty scale score = 4), or nonfrail (clinical frailty scale score < 4). The outcomes measured included intensive care unit and hospital LOS (length of stay), need for organ support, infections, mortality at hospital discharge and mortality at 6 months post discharge. We divided the population in half according to the length of their intensive care unit stay to evaluate a possible interaction between intensive care unit length of stay and frailty.

Results: The mean age was 63.2 years, and 66% were male. The mean SAPS II score was 41.8. Frailty was observed in 23.0% of the patients. Frail patients had higher hospital mortality (39.0% frail patients versus 28.2% prefrail patients versus 11.8% nonfrail patients) and 6-month mortality (frail 49.4% frail patients versus 30.6% prefrail patients versus 15.6% nonfrail patients). Patients with longer intensive care unit stays had higher 6-month mortality rates than did those with shorter intensive care unit stays did, which resulted in more frail patients: odds ratio (95% confidence interval) 3.1 (1.2 - 7.8) versus odds ratio 1.8 (0.9 - 4.0) in nonfrail patients.

Conclusion: Frailty may significantly impact hospital and 6-month mortality. In our cohort, a longer intensive care unit length of stay was associated with worse long-term outcomes, especially in frail patients.