Meropenem antimicrobial stewardship program: clinical, economic, and antibiotic resistance impact

There are few prospective studies with sufficient duration in time to evaluate clinical and antibiotic resistance impact of antibiotic stewardship programs (ASP). This is a descriptive study between January 2012 and December 2017, pre-post intervention. A meropenem ASP was initiated in January 2015; in patients who started treatment with meropenem, an infectious disease physician performed treatment recommendations to prescribers. Prospective information was collected to evaluate adequacy of meropenem prescription to local guidelines and to compare results between cases with accepted or rejected intervention. Analysis was performed to verify variables associated with intervention acceptance and with any significant change in meropenem consumption, hospital-acquired multidrug-resistant (MDR) bloodstream infections (BSIs), and 30-day all-cause crude death in MDR BSIs. Adequacy of meropenem prescription and de-escalation from meropenem treatment to narrower-spectrum antibiotic improved progressively over time, after ASP implementation (p < 0.001). Interventions on prescription were performed in 330 (38.7%) patients without meropenem justified treatment; in 269, intervention was accepted and in 61 not. Intervention acceptance was associated with shorter duration of treatment, cost, and inpatient days (p < 0.05); intervention rejection was not associated with severity of patient. During the period 2015-2017, meropenem consumption decreased compared with 2012-2014 (rate ratio [RR] 0.67; 95% CI 0.58-0.77, p < 0.001). Also decreased were hospital-acquired MDR BSI rate (RR 0.63; 95% CI 0.38-1.02, p = 0,048) and 30-day all-cause crude death in MDR BSIs (RR 0.45; 95% CI 0.14-1.24, p = 0.096), coinciding in time with ASP start-up. The decrease and better use of meropenem achieved had a sustained clinical, economic, and ecological impact, reducing costs and mortality of hospital-acquired MDR BSIs.