# Associations between suppressive antibiotic therapy, treatment failure, and side effects among young, immunocompetent veterans with prosthetic joint infection who undergo debridement, antibiotics, and implant retention

## TL;DR

This study examines how suppressive antibiotic therapy affects treatment outcomes and side effects in younger, immunocompetent veterans with joint infections.

## Contribution

The study provides new insights into the effectiveness and risks of suppressive antibiotic therapy in younger, immunocompetent patients with prosthetic joint infections.

## Key findings

- Short- and long-term suppressive antibiotic therapy were associated with reduced treatment failure or mortality.
- Short-term suppressive antibiotic therapy significantly increased the risk of C. difficile infection and antibiotic-associated diarrhea.
- Long-term suppressive antibiotic therapy was not significantly associated with treatment failure alone.

## Abstract

Suppressive antibiotic therapy (SAT) is used to prevent recurrent prosthetic joint infections (PJI) among patients who undergo debridement, antibiotics, and implant retention (DAIR). We aimed to assess SAT outcomes among younger, immunocompetent patients.

Retrospective cohort study.

Immunocompetent patients <65 years of age who received DAIR for PJI of the hip, knee, or shoulder.

Veterans Affairs hospitals.

SAT was divided into short-term (oral antibiotics given for <3 months after guideline concordant therapy) and long-term SAT (>3 months to 5 years of oral antibiotics). The primary outcome was treatment failure (TF) and mortality combined. SAT was a time-dependent covariate in Cox proportional hazards models.

Of the 938 patients, 15% received short-term SAT, 20% received long-term SAT, and 65% did not receive SAT. Short- and long-term SAT were significantly associated with decreased hazards of TF or mortality (short-term SAT adjusted hazard ratio (aHR) = 0.27; 95% confidence interval (CI): 0.11, 0.67; Long-term SAT aHR = 0.52; 95% CI: 0.30, 0.89). Short-term SAT was significantly associated with C. difficile infection (aHR: 3.47; 95% CI: 1.38, 8.74). Short-term SAT (aHR: 7.83; 95% CI: 4.80, 12.77) and long-term SAT (aHR: 1.68; 95% CI: 1.19, 2.38) were significantly associated with antibiotic-associated diarrhea. Long-term SAT was not significantly associated with TF alone (aHR = 0.61; 95% CI: 0.32, 1.16).

SAT was significantly associated with decreased death or TF and increased side effects. Benefits and risks must be weighed before prescribing SAT to younger, immunocompetent patients.