Rifampin Based Therapy for Patients with Staphylococcus aureus Native Vertebral Osteomyelitis: A Systematic Review and Meta-Analysis

Background: Native vertebral osteomyelitis (NVO) caused by Staphylococcus aureus is associated with high risk of treatment failure and increased morbidity. The role of rifampin-based therapy for the treatment of this condition is controversial. The goal of this systematic review and meta-analysis is to explore the efficacy and safety of rifampin-based therapy for the treatment of S. aureus NVO. Methods: We searched Cochrane, Embase, Medline, Scopus, and Web of Science databases for studies published up to May 2023, focusing on adults with NVO treated with or without rifampin containing regimens. A random-effects model meta-analysis estimated relative risks (RR) and risk difference (RD) with 95% confidence intervals (CI). Results: Thirteen studies (two RCTs and 11 comparative cohort studies), comprising 244 patients with S. aureus NVO who received rifampin and 435 who did not were analyzed. Meta-analysis showed that rifampin-based regimens were associated with lower risk of clinical failure (RD -14%; 95% CI: -19%, -8%; P < 0.001; I2 = 0%; RR 0.58, 95% CI: 0.37, 0.92, P = 0.02, I2 = 21%). Only one study reported on adverse events. All studies had a high or uncertain risk of bias, and the certainty of evidence was rated as very low. Conclusion: Adjunctive rifampin therapy might be associated with lower risk of S. aureus NVO treatment failure, however, the low certainty of evidence precludes drawing definitive conclusions that would alter clinical practice. A randomized trial is necessary to corroborate these findings.