Wednesday, September 26, 2018 3:35 PM – 5:05 PM How to Avoid Complications

BACKGROUND CONTEXT National estimates of Staphylococcus aureus infections after elective spinal surgeries based on microbiology results are limited. PURPOSE We assessed 180-day S. aureus cumulative incidence after elective spinal surgeries in real-world hospital settings and projected the US national burden of such infections. STUDY DESIGN/SETTING Observational study of the US Premier Healthcare Database (PHD). PATIENT SAMPLE Adults ≥18 years with spinal surgery performed during an elective inpatient or hospital-based outpatient encounter from 6/1/2010 to 6/30/2015. Elective admissions were defined according to hospital UB-04 forms. Encounters with first procedures >2 days after admission, emergency department charges, or without availability of 180-day continuous postprocedure reporting by the facility were excluded. Spinal surgeries included laminectomy (N=19,281 inpatient; 24,712 outpatient), fusion-primary (N=65,135 inpatient; 7,555 outpatient), fusion-revision (N=3,828 inpatient; 112 outpatient), and “other” spinal surgery (vertebral fracture repair, lesion excision, meningocele repair, chordotomy) (N=3,670 inpatient; 8,953 outpatient), which were defined using ICD-9-CM procedure and CPT codes according to established National Hospital Surveillance Network (NHSN) groupings and other procedure codes. If greater than one surgery was performed, one procedure per discharge was assigned according to highest expected NHSN infection risk. OUTCOME MEASURES Outcomes included overall and invasive S. aureus infections within 180-days of elective spinal surgery. Microbiology results and ICD diagnosis codes were used to define invasive (eg, bloodstream, deep wound and organ/space SSI) and overall (ie, invasive, superficial SSI, UTI, and respiratory) infections. METHODS Postsurgical S. aureus infection incidence estimates were calculated using data from 181 representative PHD hospitals reporting microbiology results. To estimate the national infection burden, surgery-specific S. aureus incidence proportions were multiplied by the number of nationally projected inpatient elective surgeries (overall and by category), calculated using surgery counts in the entire PHD (N=665 hospitals) and established weights based on hospital characteristics. RESULTS Among 91,914 inpatient elective spinal surgeries, overall and invasive S. aureus infection incidence within 180-days was 1.10% and 0.50%, respectively. The “other spine” category had the highest infection incidence (1.83% overall; 1.04% invasive), followed by fusion-revision (1.62% overall; 0.76% invasive), laminectomy (1.09% overall; 0.49% invasive), and fusion-primary (1.03% overall; 0.45% invasive). Nationally, this translated to an estimated annual 4,539 S. aureus infections (2,054 invasive) among 413,673 elective inpatient spinal surgeries. Following 41,332 hospital-based outpatient elective spinal surgeries performed at microbiology-reporting PHD hospitals, 180-day overall and invasive S. aureus incidence was 0.73% and 0.32%, respectively. CONCLUSIONS To our knowledge, this is the most comprehensive estimate of US postsurgical S. aureus infection incidence among elective spinal surgeries based on real-world microbiology data. These results may help guide targeted infection prevention efforts. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.