Prognostic value of 48-h reassessment of a laboratory-derived frailty index in ICU patients with sepsis: model development in MIMIC-IV and external transport evaluation

The study examined the prognostic value of a laboratory-derived frailty index (FI-lab-23) calculated from 23 routine laboratory parameters in ICU patients with sepsis. The research included 6,153 patients from the MIMIC-IV database with 1,594 deaths and an external cohort of 328 patients from a single center with 85 deaths. Each 0.05 increase in the index during the 24-48 hour period was associated with higher risk of death within 28 days (OR: 1.178). The model developed on MIMIC-IV data achieved an optimism-corrected area under the curve (AUC) of 0.710, while external application to the local cohort achieved an AUC of 0.774. Reassessment of the index at 24-48 hours provided updated prognostic information for predicting 28-day mortality. However, the authors emphasize that this constitutes supportive evidence and larger multicenter studies are required before clinical implementation.