OPAT in Switzerland: single-center experience of a model to treat complicated infections

Purpose Outpatient parenteral antimicrobial therapy (OPAT) programmes are established in the minority of Swiss hospitals. We aimed to study the OPAT programme at the University Hospital Basel during a 3-year period to evaluate safety and outcome. Methods All patients treated in the OPAT programme between 2015 and 2017 were included in the study. Demographic, clinical and OPAT outcome data were extracted from the hospital information system. Differences between treatment periods were analysed and risk factors for readmission and adverse events identified. Results In total, 462 patients were enrolled from 2015 to 2017. Patient numbers and total treatment days increased by 68% and 116%, respectively. Indications included many complicated infections such as bone and joint (23%) and intravascular infections (13%). Of the identified Gram-negative bacteria, 25% produced extended spectrum beta-lactamases. The percentage of antibiotics administrated with an elastomeric device increased from 11% in 2015 to 29% in 2017, whereas the use of once-daily antimicrobials (such as ceftriaxone) declined. Adverse events were rare (n = 67; 14.6%) including only two severe catheter-related events. Cure was noted in 98% of patients. 30-day unplanned readmission occurred in 46 (10.0%) patients, and intravascular infections and a higher Charlson comorbidity index were identified as independent predictors. Conclusion This study demonstrates the successful implementation of a formal OPAT programme in a Swiss tertiary care hospital. Careful selection of patients and monitoring during treatment are crucial to avoid frequent readmissions. Hence, our data call for an expansion of OPAT services in Switzerland in the near future.