Abstract and Introduction
Abstract
Objective To determine the frequency, mortality, cost, and risk factors associated with readmission after index hospitalization with severe sepsis.
Design Observational cohort study of Healthcare Cost and Utilization Project data.
Setting All nonfederal hospitals in three U.S. states.
Patients Severe sepsis survivors (n = 43,452) in the first two quarters of 2011.
Interventions None.
Measurements and Main Results We measured readmission rates and the associated cost and mortality of readmissions in severe sepsis survivors. We used multivariable logistic regression to identify patient and hospitalization characteristics associated with readmission. Of 43,452 sepsis survivors, 26% required readmission within 30 days and 48% within 180 days. The cumulative mortality rate of sepsis survivors attributed to readmissions was 8%, and the estimated cost was over $1.1 billion. Among survivors, 25% required multiple readmissions within 180 days and accounted for 77% of all readmissions. Age younger than 80 years (odds ratio, 1.14; 95% CI, 1.08–1.21), black race (odds ratio, 1.18; 95% CI, 1.10–1.26), and Medicare or Medicaid payor status (odds ratio, 1.21; 95% CI, 1.13–1.30; odds ratio, 1.34; 95% CI, 1.23–1.46, respectively) were associated with greater odds of 30-day readmission while female gender was associated with reduced odds (odds ratio, 0.92; 95% CI, 0.87–0.96). Comorbidities including malignancy (odds ratio, 1.34; 95% CI, 1.24–1.45), collagen vascular disease (odds ratio, 1.30; 95% CI, 1.15–1.46), chronic kidney disease (odds ratio, 1.24; 95% CI, 1.18–1.31), liver disease (odds ratio, 1.22; 95% CI, 1.11–1.34), congestive heart failure (odds ratio, 1.14; 95% CI, 1.08–1.19), lung disease (odds ratio, 1.12; 95% CI, 1.06–1.18), and diabetes (odds ratio, 1.12; 95% CI, 1.07–1.17) were associated with greater odds of 30-day readmission. Index hospitalization characteristics including longer length of stay, discharge to a care facility, higher hospital annual severe sepsis case volume, and higher hospital sepsis mortality rate were also positively associated with readmission rates.
Conclusion The 30-day and 180-day readmissions are common in sepsis survivors with significant resultant cost and mortality. Patient sociodemographics and comorbidities as well as index hospitalization characteristics are associated with 30-day readmission rates.
Introduction
Hospital readmissions are common and have far-reaching implications for patients and society. Approximately 20% of discharged Medicare beneficiaries are rehospitalized within 30 days of discharge, whereas 34% are rehospitalized within 90 days. Readmissions impact quality of life and represent a significant cost burden to the U.S. healthcare system with annual costs estimated to be $17 billion in Medicare recipients alone. Hospital readmission within 30 days of discharge has been associated with substandard care during the index admission and inadequate postdischarge care processes. This has led to the assertion that a proportion of readmissions are avoidable although estimates of this proportion vary widely. Accordingly, the Patient Protection and Affordable Care Act has mandated that hospitals reduce readmissions for heart failure, myocardial infarction, and pneumonia. Starting in 2013, the Center for Medicare and Medicaid Services began tying reimbursement rates for all diagnosis-related groups to the readmission rates for these common and costly diagnoses.
Similarly, severe sepsis is a disease of high prevalence and cost. Evaluation of Medicare claims shows an increasing prevalence of severe sepsis with over 1 million annual admissions, whereas the total annual cost of sepsis admissions now exceeds $20 billion in the United States. Approximately 850,000 Medicare patients survived admission for severe sepsis in 2008, representing a large population at risk of hospital readmission given large comorbidity burdens and adverse cognitive and functional sequelae. Despite the size and fragility of this population, little is known about its readmission rates or their associated cost and risk factors.
Quantifying the scope of readmissions in severe sepsis survivors and identifying risk factors may inform policy and facilitate identification of high risk-patients for future targeted intervention. Thus, we evaluated readmission patterns, potential risk factors, and cost after an index admission with severe sepsis in a large administrative database. The objectives of this study were to 1) quantify the frequency of 30-day readmissions in severe sepsis survivors, 2) identify associations between patient and/or index hospitalization characteristics and readmissions, and 3) determine whether readmissions are a frequent problem beyond 30 days from discharge and estimate the costs associated with these readmissions.