LAUSR

Abstract Background The main goal of an Antimicrobial Stewardship Program (ASP) is to optimize clinical outcomes while minimizing unintended consequences of antimicrobial use. However, the healthcare resource manager’s primary goal for ASP is to reduce the cost of patient care without adversely affecting quality. Globally, generic drugs facilitate access to medication, especially in resource-limited settings, provided that they prove as effective as the brand molecule. Economical evaluation (EE) studies aim to find the most cost effective alternatives. This study was designed to determine the incremental cost-effectiveness ratio (ICER) of generic meropenem (GM) use vs. brand-name meropenem (BNM) to treat Gram-negative infections. Methods We conducted a double cohort EE study of adult patients who received GM vs. patients who received BNM. All patients with meropenem-susceptible infections were treated in the intensive care unit (ICU) of a Colombian acute care hospital. Survival rates were defined as the clinical outcome for effectiveness. Total infection cost was defined by the cost (USD) of antimicrobial consumption, length of stay, and laboratory and imaging exams until infection resolution. ICER was calculated using a decision tree model. Results A total of 168 patients were included; survival rate for the 68 patients treated with GM was 38% vs. 59% for the 100 patients treated with BNM (death risk OR: 18.4 95% CI 1.47–232, P = 0.024). The total antimicrobial consumption cost was lower in the BNM cohort ($303 vs. $588) explained by fewer consumption doses. ICU stay costs were higher in the GM cohort ($8,896 vs. $7,705), however, laboratory and imaging exam costs were lower in the GM cohort ($961 vs. $1,360). Total infection cost did not show a significant difference between groups (BNM $10,771 vs. GM $11,343 P = 0,91). The ICER, which represents the cost of obtaining one additional effectiveness unit (patient survival), is $2,724 USD when changing BNM to GM. Conclusion This study shows that the use of GM, which is less clinically effective than BNM, is not a cost effectiveness option. Our findings evidence that the use of GM instead of BNM increases the consumption of healthcare resources, increases spending and may reduces the economic sustainability of the national healthcare system. Disclosures C. Hernández-Gómez, Merck Sharp & Dohme: Consultant, Consulting fee; Pfizer: Consultant, Consulting fee; C. Pallares, Merck Sharp & Dohme, Pfizer: Consultant, Consulting fee; M. V. Villegas, Merck Sharp & Dohme: Consultant, Consulting fee and Research support; Pfizer: Consultant, Consulting fee and Research support