Association of severity of illness and intensive care unit readmission: A systematic review

Objectives: To determine whether ICU readmission is associated with higher severity of illness scores in adult patients. Background: Readmissions to the intensive care unit (ICU) are associated with increased costs, morbidity, and mortality. Methods: We performed searches of MEDLINE, EMBASE, and grey literature databases. We selected studies reporting data from adults who were hospitalized in an ICU, received severity of illness scores, and were discharged from the ICU. Characteristics of readmitted and non-readmitted patients were examined. Results: We screened 4766 publications and included 31 studies in our analysis. In most studies, severity of illness scores were higher in patients readmitted to the ICU. Readmission was also associated with higher mortality and longer ICU and hospital stays. Excessive heterogeneity precluded the reporting of results in the form of a meta-analysis. Conclusions: ICU readmission is associated with higher severity of illness scores during the same hospitalization in adult patients.