First‑Day Glycemic Exposure and 28‑Day Mortality in the ICU: A Multicenter Cohort Study

Abstract Importance: Early glycemic exposure in the ICU is common and clinically modifiable, yet bedside assessment often relies on single glucose values rather than exposure‑aware metrics. Interpretable, first-day prediction may support individualized glycemic targets and early intervention. Objective: To examine the association between first‑day time‑weighted average glucose (TWAG) and 28‑day mortality, and to evaluate GlucoSurvAI, an interpretable ensemble model for first-day risk stratification. Design, Setting, and Participants: Retrospective cohort study using electornic health records from 13 U.S. hospitals. Among 18,868 adult ICU encounters, 8,048 patients from 7 U.S. hospitals met inclusion criteria (≥1 glucose value and hospital length of stay ≥24 hours). Exposures: First‑day glycemic exposure summarized as TWAG, categorized as