Cost-utility analysis of outpatient parenteral antimicrobial therapy (OPAT) in the Brazilian national health system.

Background: Outpatient parenteral antimicrobial therapy (OPAT) has been used for decades in different countries to reduce hospitalization rates, with favorable clinical and economic outcomes. This study assesses the cost-utility of OPAT compared to inpatient parenteral antimicrobial therapy (IPAT) from the perspective of a public university hospital and the Brazilian National Health System (Unified Health System -SUS). Methods: Prospective study with adult patients undergoing OPAT at an infusion center, compared to IPAT. Clinical outcomes and quality-adjusted life year (QALY) were assessed, as well as a micro-costing. Cost-utility analysis from the hospital and SUS perspectives were conducted by means of a decision tree, within a 30-day horizon time. Results: Forty cases of OPAT (1112 days) were included and monitored, with a favorable outcome in 97.50%. OPAT compared to IPAT generated overall savings of 31.86% from the hospital perspective and 26.53% from the SUS perspective. The intervention reduced costs, with an incremental cost-utility ratio of -44,395.68/QALY for the hospital and -48,466.70/QALY for the SUS, with better cost-utility for treatment times greater than 14 days. Sensitivity analysis confirmed the stability of the model. Conclusion: Our economic assessment demonstrated that, in the Brazilian context, OPAT is a cost-saving strategy both for hospitals and for the SUS.