Intensive Care Unit (ICU) readmission: is a high readmission rate always bad?

Abstract

INTRODUCTION: The risk factors and sequelae of ICU readmission are well reported. Annual rates are reported by ANZICS, and in 2016 Epworth Richmond had a higher than expected readmission rate. Using ICU readmission rates as a quality marker without adjusting for case mix has been criticized. After 48 hours patient characteristics rather than ICU discharge circumstances have been shown to exhibit stronger associations with readmission and previous Australian guidelines have focused on ICU readmission under 72 hours. With likely increasing importance placed on readmission figures, does a high ICU readmission rate indicate deficiencies in patient care? METHODS: This was retrospective, cohort study of all readmissions in a single private, academic ICU for the 2015 calendar year. Readmissions were classified as planned or unplanned, and all unplanned readmissions were assessed in relation to the readmission timing, ICU treatment and mortality. RESULTS: There were 1906 ICU admissions of which 106 (5.6%) were readmitted. 26/106 (19%) of readmissions were pre-planned, elective surgical cases. Of the 80 unplanned readmissions, 5 (6.3%) were initially discharged from ICU after 1800hrs, and 41 %51%) were readmitted within 72 hours. The mortality rate for all patients admitted to ICU in 2015 was 2.0% (39 deaths). Of the 41 unplanned readmissions under 72 hours, 25 (61.0%) received organ support on readmission. 20 (48.8%) received respiratory support, 13 (31.7%) received cardiovascular support, and 1 (2.4%) received renal support. ICU mortality was 1/41 (2.4%). Excluding pre-planned readmissions and those after 72 hours reduces the readmission rate for 2015 to 2.2%. CONCLUSION: In 2015 the majority of ICU readmissions were either greater than 72 hours post initial discharge, or were elective, pre-planned post surgical readmissions. The mortality rate post readmission was low. Further refinement of reporting of ICU readmission rates is required if they are to be used as a quality indicator.