Quantifying cost savings from outpatient parenteral antimicrobial therapy programme: a systematic review and meta-analysis.

Background: The outpatient parenteral antimicrobial therapy (OPAT) programme was introduced to reduce costs and enhance the quality of life for patients requiring prolonged treatment with parenteral antimicrobials. However, given the escalating inflation, the extent of current cost savings achieved through OPAT programmes remains unclear. This systematic review and meta-analysis employ a cost-minimization analysis to quantify the cost savings from OPAT compared to inpatient treatment. Methods: The Cochrane Library, MEDLINE, Embase, PubMed and Web of Science databases were searched for studies comparing the costs of parenteral antimicrobial treatment without restriction on study design and year. Two reviewers conducted eligibility screening and cross-validated the extracted data. The cost data were adjusted and inflated to 2023 US dollars. A random effect model calculated mean differences (MD) with 95% confidence intervals (CI). The review protocol was registered on PROSPERO (CRD42024584201). Results: Twenty studies involving 2790 patients were included in the systematic review, and six studies (three randomized controlled trials and three cohorts) were subject to metanalysis. Collectively, these included 560 patients who received treatment in outpatient settings, and 491 treated as inpatients. The cost of parenteral antimicrobial per episode of care was lower in the outpatient settings MD -$5436.73 (95% CI: -$9589.24 to -$1284.22, I² = 96%; Conclusions: OPAT significantly saves costs compared to inpatient treatment. We recommend comprehensive analysis of treatment costs from all perspectives, including various cost types.