Risk factors associated with return sepsis admission following emergency department discharge with infection

Abstract

Introduction: Despite sepsis having growing awareness nationally, efforts to reduce the public health impact of sepsis have lagged. Although there are known pathophysiologic mechanisms and preventive strategies, sepsis is rarely approached as a predictable or preventable condition. Predicting who will develop sepsis in patients with infection still remains a challenge. This study examined modifiable and nonmodifiable risk factors associated with patients initially discharged home with an infection and had future sepsis-related admissions within 7 days of the index Emergency Department (ED) visit.

Methods: We conducted a multi-center retrospective cohort analysis of adults presenting to two university hospital EDs. The inclusion criteria encompassed adult patients who were discharged from the ED at their index visit with discharge diagnosis (ICD 10-CM code) of pneumonia, urinary tract infection (UTI), and/or cellulitis and who returned for hospital admission within 7 days of the index visit due to sepsis, severe sepsis without septic shock, and/or septic shock. Using multivariate regression, risk factors that predict return sepsis admission within 7 days of ED index visit were evaluated, and a 7-day return sepsis admission model was constructed. The predictive power of the model was measured by c-statistic.

Results: Among 10,179 unique ED patients, return sepsis admissions within 7 days occurred in 113 visits (1.11 % of discharged patients). Statistically significant risk factors among patients with infection associated with subsequent sepsis admission in the chosen model were Cardiovascular Disease (OR 2.07 95 % CI 1.26-3.42), Hypertension (OR 2.21 95 % CI 1.37-3.56), Chronic Kidney Disease (OR 1.80 95 % CI 1.11-2.91), Cancer (OR 2.22 95 % CI 1.43-3.45), Male (OR 1.67 95 % CI 1.13-2.45), arriving in an ambulance (vs. walk in OR 2.55 95 % CI 1.46-4.44), higher heart rate (OR 1.29 95 % CI 1.16-1.45), and higher temperature (OR 1.23 95 % CI 1.05-1.45), Hyperlipidemia was protective (OR 0.56 95 %CI 0.34-0.91). The c-statistic of our chosen model was 0.77 (95 % CI 0.73-0.81). The Hosmer-Lemeshow test for our logistic regression model resulted in a chi-square value of 7.23 with 8 degrees of freedom with a p-value of 0.51. This suggests that our model fits the data well.

Conclusion: Our findings may be used to risk stratify and guide outpatient disposition decisions for ED patients with infection and to determine which patients need to be more closely monitored in the outpatient setting following ED discharge.

Keywords: Outpatient; Prediction model; Return admission; Risk factors; Risk stratification; Sepsis; Sepsis admission.