Incidence and Etiology of Potentially Preventable ICU Readmissions

Objectives: The rate of unplanned ICU readmissions is often considered a measure of hospital performance. However, the degree to which these readmissions are preventable and the causes of preventable readmissions are unknown, creating uncertainty about the feasibility and value of reducing ICU readmission rates. To inform this issue, we sought to determine the frequency and underlying causes of potentially preventable ICU readmissions. Design: Retrospective cohort study. Setting: Urban, academic medical center in the mid-Atlantic United States. Patients: Adult patients discharged alive from their first ICU admission with an unplanned readmission within 48 hours of discharge. Measurements and Main Results: Each patient's medical chart was reviewed by two independent investigators who rated each readmission's preventability according to standardized scale and assessed the etiology of both preventable and nonpreventable readmissions. We assessed concordance between raters using the kappa statistic and resolved disagreements through iterative discussion. Of 136 readmissions in the final analysis, 16 (11.8%; 95% CI, 6.9-18.4) were considered preventable and 120 (88.2%; 95% CI, 81.5-93.1) were considered nonpreventable. Of nonpreventable readmissions, 67 were due to a new clinical problem and 53 were due to an existing clinical problem. Among preventable readmissions, six were attributable to system errors, six were attributable to management errors, two were attributable to procedural events, one was attributable to a diagnostic error, and one was attributable to a medication error. Compared to nonpreventable readmissions, preventable readmissions tended to have shorter index ICU lengths of stay (2 vs 3 d; p = 0.05) and a shorter duration of time on the ward prior to readmission (16.6 vs 23.6 hr; p= 0.05). Conclusions: The majority of early ICU readmissions are nonpreventable, raising important concerns about ICU readmission rates as a measure of hospital performance.