Oral Versus Standard Antimicrobial Treatment for Pyogenic Native Vertebral Osteomyelitis: A Single-Center, Retrospective, Propensity Score-Balanced Analysis
Abstract
Background
Interest in shorter antimicrobial regimens and oral treatment for osteoarticular infections is growing. The aim of this study is to assess whether there is an association between the administration of an entirely oral antibiotic therapy (OT) and the clinical outcome of native vertebral osteomyelitis (NVOs).
Methods
We conducted a single-center, retrospective, observational study on consecutive patients with pyogenic NVOs over a 10-year period (2008–2018). We performed multivariate logistic regression analysis to identify risk factors for clinical failure, both in the whole population and in subgroups. The impact of OT versus standard treatment (intravenous induction followed by oral treatment whenever possible) was assessed in patients with a non-multidrug-resistant microorganism (MDRO) etiology, and the impact of a rifampin-containing regimen was assessed in patients affected by NVOs caused by staphylococci or of unknown etiology.
Results
The study population included 249 patients, and 33 (13.3%) experienced clinical failure; the OT group consisted of 54 patients (21.7%). Multivariate regression analysis of the whole population selected Charlson comorbidity index (adjusted odds ratio [aOR], 1.291; 95% confidence interval [CI], 1.114–1.497; P = .001) and MDRO etiology (aOR, 3.301; 95% CI, 1.368–7.964; P = .008) as independent factors for clinical failure. Among patients affected by a non-MDRO NVO, OT was not associated with an increased risk of clinical failure (aOR, 0.487; 95% CI, .133–1.782; P = .271), even after adjustment for the propensity score of receiving OT. In the subgroup of patients with staphylococcal or unknown etiology, NVO rifampin was independently associated with favorable outcome (aOR, 0.315; 95% CI, .105–.949; P = .040).
Conclusions
An entirely oral, highly bioavailable treatment, including rifampin, may be as effective as parenteral treatment in selected patients with NVOs.
Publication
Open Forum Infectious Diseases
Notes
Key Question: Is oral antibiotic therapy non-inferior to intravenous antibiotic therapy for the treatment of native vertebral osteomyelitis (NVO) caused by non-multidrug resistant organisms?
Key Findings:
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In 249 patients with pyogenic NVO, the overall failure rate was 13%. Higher Charlson comorbidity index and multidrug-resistant organism (MDRO) etiology were risk factors for worse prognosis.
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In the subgroup of 213 patients with non-MDRO NVO, there was no significant difference in treatment failure between the oral therapy (OT) group (5.6% failure) and the standard therapy (ST) group (12.6% failure) that received initial intravenous antibiotics (p=0.20).
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After adjusting for propensity score, oral therapy was not associated with increased risk of failure compared to standard therapy for non-MDRO NVO.
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Among patients with staphylococcal NVO or unknown etiology, rifampin-based regimens were independently associated with better clinical outcomes.
Clinical Implications:
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For patients with pyogenic NVO caused by non-MDROs, highly bioavailable oral antibiotic therapy may be an effective alternative to standard intravenous therapy. This could reduce invasiveness, inconvenience, and costs.
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Rifampin should be included in the antibiotic regimen for staphylococcal NVO or when etiology is unknown.
Strengths:
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Relatively large sample size
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Adjusted for propensity score to account for potential confounding factors
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Findings consistent with other studies showing efficacy of oral antibiotics for bone/joint infections
Limitations:
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Single center retrospective study
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Non-randomized comparison of oral vs intravenous antibiotics
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Antibiotic choice at discretion of treating physician
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Some loss to follow up
Citation
1.
Marconi L, Tedeschi S, Zamparini E, et al. Oral Versus Standard Antimicrobial Treatment for Pyogenic Native Vertebral Osteomyelitis: A Single-Center, Retrospective, Propensity Score-Balanced Analysis. Open Forum Infectious Diseases. 2022;9(8):ofac366.