LAUSR

Background Patients with a reported penicillin allergy (PA) receive alternative antibiotics that may not be as effective as cephalosporins for surgical site infection (SSI) prophylaxis. While patient-reported PA has been correlated to increased complications in other fields, this has not been conclusively shown in spine surgery. We investigate the impact of PA on 90-day complications and inpatient charges/costs after elective posterior lumbar fusion between PA and non-PA cohorts. Methods The 2005 to 2014 SAF100 database was queried using International Classification of Diseases, Ninth Edition (ICD-9) procedure codes to identify patients undergoing elective posterior lumbar fusions. The reported PA ICD-9 code was used to divide the study sample into a PA cohort and non-PA cohort. Multivariate logistic regression analyses were used to assess significant differences in 90-day complications between PA and non-PA groups after controlling for confounding factors. Generalized linear regression modeling was used to assess for differences in inpatient charges and costs. Results A total of 286,042 patients, 7497 (2.6%) of whom reported a PA, who underwent elective posterior lumbar fusions were included. Following adjustment for confounding factors, patients in the PA group had significantly higher odds of experiencing SSIs (3.8% vs 3.1%, OR 1.20 [95% CI 1.07–1.36]; P = 0.002), urinary tract infections (12.3% vs 10.0%, OR 1.16 [95% CI 1.08–1.24]; P < 0.001), sepsis (1.5% vs 1.2%, OR 1.24 [95% CI 1.02–1.50]; P = 0.026), acute kidney injuries (3.8% vs 3.2%, OR 1.19 [95% CI 1.05–1.34]; P = 0.006), readmissions (9.8% vs 8.5%, OR 1.15 [95% CI 1.07–1.25]; P < 0.001), increased inpatient charges (+$4340; P < 0.001), and increased reimbursements (+$1221; P < 0.001). Conclusions Patients with a reported PA experienced significantly higher rates of 90-day complications and cost following elective posterior lumbar fusion. The findings of the study highlight the importance of preoperative PA testing to minimize the use of alternative antibiotics and potentially improve patient outcomes. Clinical Relevance Patients should be tested for penicillin allergy to minimize the use of alternative antibiotics among patients with a reported PA. Level of Evidence 3.