Association between Physiological Abnormalities on General Ward and Patient Outcomes after Intensive Care Unit Readmission: A Cross-Sectional Study

BACKGROUND: Readmissions to the intensive care unit (ICU) serve as critical quality indicators reflecting the continuum of care between critical and general care settings. This study aimed to evaluate the prognostic significance of vital sign deterioration alerts and rapid response system (RRS) notifications in patients readmitted to an ICU. METHODS: We conducted a retrospective analysis of demographic and clinical data from subjects readmitted to the ICU within 7 days of transfer to a general ward between 2019-2021. Associations between vital sign alerts, RRS notifications, and patient outcomes, particularly in-hospital mortality, were examined using restricted cubic spline (RCS) method to explore potential non-linear relationships. RESULTS: Among 23,438 patients discharged from the ICU, 474 (2.02%) were readmitted within 7 days, predominantly male (59.7%) and mostly transferred from medical general wards (53.6%). The median duration of stay in the general ward prior to ICU readmission was 3.1 days, with a subsequent hospital stay of 25.2 days. Early ICU readmissions <72 hours (P = .014) and vital sign (P = .011) alerts were significantly associated with increased mortality rates. RCS analysis revealed a U-shaped relationship between the timing of first vital sign alerts and mortality, indicating increased risks with very early and late alerts; a more extended ward stay before ICU readmission was linearly correlated with lower mortality. CONCLUSION: Early ICU readmissions, early vital sign deterioration alerts, and the alert-readmission interval were key determinants of patient outcomes. These findings underscore the importance of timely interventions for patients exhibiting both early and late signs of deterioration to enhance survival outcomes.