Risk factors for 30-day readmission among patients with culture-positive severe sepsis and septic shock: A retrospective cohort study

BACKGROUND: With decreasing mortality in sepsis, attention has shifted to longer-term consequences associated with survivorship. Thirty-day readmission as a component of healthcare utilization is an important outcome. OBJECTIVE: To examine the frequency of and risk factors for 30-day readmission among patients surviving sepsis. DESIGN: Single-center retrospective cohort. METHODS/SETTING: We examined 30-day readmission risk among survivors of hospitalization with culture-positive severe sepsis or septic shock. Extended spectrum β-lactamase (ESBL) organisms were identified via molecular laboratory testing. Healthcare-associated (HCA) was defined by 1 of the following: (1) recent hospitalization, (2) immune suppression, (3) nursing home residence, (4) hemodialysis, (5) prior antibiotics, and (6) index bacteremia hospital-acquired (onset >2 days following admission). Acute kidney injury (AKI) was defined according to the RIFLE (Risk, Injury, Failure, Loss, End-stage) criteria. Logistic regression modeled predictors of 30-day readmission. RESULTS: Among 1697 sepsis survivors, 543 (32.0%) required 30-day readmission. Readmitted patients had a higher chronic (median Charlson score 5 vs 4, P < 0.001) but not acute (median APACHE [Acute Physiology and Chronic Health Evaluation] II score 15 and 15, P = 0.275) illness burden, and higher prevalence of HCA sepsis (94.2% vs 90.2%, P = 0.014) than nonreadmitted survivors. In logistic regression, 3 factors increased (Organism: ESBL [odds ratio {OR}: 4.50, 95% confidence interval {CI}: 1.43-14.19], RIFLE: Injury or RIFLE: Failure [OR: 1.95, 95% CI: 1.300-2.93], and Organism: Bacteroides spp [OR: 2.04, 95% CI: 1.06-3.95]) and 2 reduced (Source: Urine [OR: 0.58, 95% CI: 0.35-0.98], Organism: Escherichia coli [OR: 0.49, 95% CI: 0.27-0.90]) the odds of 30-day readmission. CONCLUSIONS: One-third of survivors of severe sepsis/septic shock required 30-day readmission. Mild-to-moderate AKI nearly doubled its risk. Journal of Hospital Medicine 2015;10:678-685.