Factors associated with outcome and duration of therapy in outpatient parenteral antibiotic therapy (OPAT) patients with skin and soft-tissue infections.

This study was designed to identify factors associated with adverse outcomes and increased duration of parenteral therapy in patients with skin and soft-tissue infections (SSTIs) managed with outpatient parenteral antibiotic therapy (OPAT). A retrospective cohort study interrogating variables recorded prospectively in an electronic OPAT patient database was performed. 'OPAT failure' was defined as hospitalisation following initiation of OPAT, or adverse event or progression of infection necessitating a change in antibiotic therapy. Variables associated with failure or increased duration of therapy were identified via univariate and multiple logistic regression analyses. In total, 963 first patient episodes of OPAT-treated SSTIs were observed; 84% were treated with daily ceftriaxone and 15% with teicoplanin (three daily loading doses then three times per week). Progression of infection was observed in 2.8% of cases, inpatient management was required in 6% and significant adverse events occurred in 7.1%. Overall OPAT success was 87.1%. Female sex, diabetes and treatment with teicoplanin were independently associated with OPAT failure. A significant reduction in duration of OPAT therapy was observed over time. A longer duration of intravenous therapy was associated with meticillin-resistant Staphylococcus aureus (MRSA), older age, vascular disease, a diagnosis of bursitis, and treatment with teicoplanin. Non-inpatient referrals, management via a nurse-led patient group direction, and treatment with ceftriaxone were associated with reduced duration of OPAT. For selected patients with SSTIs, OPAT was generally safe and effective, but specific patient groups were identified with more complex management pathways and poorer outcomes.