Night-shift Discharge from Intensive Care Unit Increases the Mortality-risk of ICU Survivors

Abstract

Intensive Care (ICU) survivors discharged from ICU to the general ward at night have a higher mortality1,2. We sought to clarify which factors, including night-shift discharge, influence outcome following ICU discharge in a metropolitan hospital, using a cohort study of critically-ill patients between 1/1/1999-30/4/2003. Patients were excluded from analysis if they (a) died in ICU, (b) were transferred to another hospital, (c) had an ICU length of stay <8 hours, or (d) age <16 years. Logistic regression was used to derive a predictive model based on the following variables: patient demographics, severity of illness following ICU admission (APACHE II mortality-risk, pm), final diagnosis, discharge timing including premature or delayed (>4 hours) ICU discharge, and “limitation of medical treatment” orders. The outcome measures were patient status at hospital discharge and ICU readmission rate. Of the 1870 ICU survivors, 92 (4.9%) died after discharge from ICU. Patients discharged to the ward during the night-shift (2200-0730 hours) had a higher APACHE II score and crude mortality. The difference in APACHE II pm did not reach statistical significance. No significant calendar or seasonal pattern was identified. Logistic regression identified night-shift discharge (RR=1.7; 95% CI 1.03-2.9; P=0.03), limited medical treatment order (RR=5.1; 95% CI 2.2-12) and admission APACHE II pm (RR=3.3; 95% CI 1.3-7.6) as independent predictors of patient outcome following ICU transfer to the ward. Conclusion: At the time of ICU discharge to the ward three factors are predictive of hospital outcome: timing of ICU discharge, limited medical treatment orders and initial illness severity.