JMIR Publications

ABSTRACT

Background:

ICU discharge decisions rely largely on subjective clinician judgment and on severity scores such as the Sequential Organ Failure Assessment (SOFA), which were designed to quantify organ dysfunction rather than to assess discharge readiness. No validated tool systematically evaluates discharge readiness from the physiological parameters routinely monitored at the ICU bedside.

Objective:

We developed and internally validated the ICU Discharge Readiness Score (iDRS), a two-tier screening tool for ICU discharge readiness using bedside physiological parameters and minimal laboratory data.

Methods:

Using the MIMIC-IV v3.1 database (2008–2022), we constructed daily 08:00 assessment grids for 76,801 ICU stays, generating 266,070 assessment points. iDRS employs a two-tier structure: Tier 1 automatically assigns a score of zero to patients receiving active life-sustaining treatments; Tier 2 scores the remaining patients across four physiological domains (respiratory, hemodynamic, neurological, renal/perfusion) on a 0–8 scale. Discriminative performance was evaluated using AUROC, compared against the SOFA score via the Paired patient-level cluster bootstrap, and supplemented by decision curve analysis and discordant case characterization. Temporal validation across early (2008-2016) and recent (2017-2022) cohorts was performed.

Results:

iDRS achieved an AUROC of 0.750 (95% CI 0.747–0.753), significantly outperforming SOFA (0.650; P<.001). At the optimal cutoff of ≥5, sensitivity was 0.895 and NPV was 0.949. Decision curve analysis demonstrated superior net benefit across clinically relevant thresholds. Discordant case analysis revealed that discharge failure was associated with chronic comorbidity burden (Charlson index r = −0.169) and hospitalization complexity (hospital LOS r = −0.367) rather than acute organ dysfunction. Temporal validation confirmed stable performance across both periods (AUROC 0.756 vs. 0.738).

Conclusions:

iDRS demonstrated superior discrimination over SOFA with high sensitivity and NPV, supporting its role as a bedside screening tool that complements clinician judgment in ICU discharge decision-making.