Cost and Hospital Resource Utilization of Staphylococcus aureus Infection Post Elective Posterior Instrumental Spinal Fusion Surgeries in the United States: a Retrospective Cohort Study

Abstract

Surgical site infections (SSIs) and blood stream infection (BSI) post spinal fusion surgeries have been reported to be associated with worse clinical outcomes and increased costs. Economic data pertinent to the most common pathogen Staphylococcus aureus (S. aureus) infections after spinal fusion surgeries were limited. This study assessed cost and hospital resource utilization for S. aureus infection within 180 days post elective posterior instrumental spinal fusion surgeries during 2010−2015. A retrospective cohort study using hospital discharge and microbiology data from 129 US hospitals included in Premier Healthcare Database was conducted. Patients (age ≥ 18 years) who were electively admitted during 2010−2015 with a primary or secondary ICD9 procedure code for posterior instrumental spinal fusion surgeries were analyzed. Culturally confirmed S. aureus infection status was classified as invasive S. aureus infection (i.e., BSI, deep or organ/space SSIs), any S. aureus infection, and no S. aureus infection. Outcomes included total hospitalization cost, length of stay (LOS) and risk of all cause readmission. Multivariable regression analyses were used to compare costs and hospital resource utilizations between infection and no infection groups. 151 patients were identified with invasive infection, 308 with any infection, and 12918 with no infection. Compared with no S. aureus infection group, invasive and any S. aureus infection groups had significantly higher total hospitalization cost (Adjusted mean cost in 2015 U.S. dollars: $88381 and $64838 Vs. $47358, P values<0.001), longer LOS (Adjusted mean: 24.68 and 15.29 Vs. 7.97 days, P values<0.001), and higher risk of readmission (Adjusted risk ratio: 2.14 (95% confidence interval [CI]: 2.05, 2.24) for invasive and 1.69 (95% CI: 1.60, 1.78) for any S. aureus infection group). S. aureus infections post elective posterior instrumental spinal fusion surgeries are associated with significantly higher hospitalization cost, LOS and risk of readmission within 180 days post-surgery. They presented a substantial burden to hospitals and patients. More effective infection control measures are warranted to reduce infections and improve patient outcomes. N. Rosenthal, Pfizer Inc.: Research Contractor, Research grant; K. Heinrich, Pfizer Inc.: Employee, Salary; J. Chung, Pfizer Inc.: Research Contractor, Research grant; H. Yu, Pfizer Inc.: Employee, Salary