Predictors of Readmission following Discharge of Patients with Gram-Negative Bacteremia: A Retrospective Cohort Study

Abstract

Background: Short-term readmission is an important outcome reflecting the poor trajectory of sepsis survivors. The aim of this study was to identify the major risk factors for 30-day readmission among patients with gram-negative bacteremia. Methods: This was a retrospective cohort study including all consecutive adults hospitalized in the medical departments in a referral hospital in Israel with gram-negative bacteremia between 2011 and 2020, who were discharged alive. Predictors for 30-day readmission were investigated, considering death after discharge as a competing event. Cephalosporin resistance was our predictor of interest. Subdistribution hazard ratios (HRs) of the cumulative incidence function were investigated using the Fine and Gray multivariable competing-risk regression model. The prediction models were cross-validated using the k-fold method. Results: Among 2196 patients surviving hospitalization with gram-negative bacteremia, the mean age was 70 ± 16 years and 432 (19.6%) were readmitted within 30 days. Variables associated with readmission hazards were Arab ethnicity, active malignancy, conditions requiring immunosuppression, anxiolytics or hypnotics, anticoagulant or antiplatelet therapy, discharge with a nasogastric tube, higher predischarge heart rate, duration of antibiotic therapy during hospitalization, and bacteremia caused by cephalosporin-resistant bacteria (HR, 1.23 [95% confidence interval {CI},. 99-1.52]). The area under the receiver operating characteristic curve for this model was 75.5% (95% CI, 71.3%-79.1%). In secondary models, cephalosporin resistance, inappropriate empirical antibiotic treatment, and lower predischarge albumin were significantly associated with readmission. Conclusions: Thirty-day readmissions among patients with gram-negative bacteremia surviving the index admission were high. Readmission was related to comorbidities and infections caused by multidrug-resistant infections. Main point: Among 2196 adults surviving hospitalization with gram-negative bacteremia, 432 (19.6%) were rehospitalized within 30 days. Comorbidities, inappropriate empirical antibiotic treatment, bacteremia caused by cephalosporin-resistant bacteria, predischarge heart rate, and albumin were associated with readmissions.