Staphylococcus Aureus: Selective Reporting of Antibiogram Results and Its Impact on Antibiotic Use. Interventional Study with a Reference Group on the Effect of Switching from Non-Selective to Selective Antibiotic Reporting

Abstract

Background:Antimicrobial stewardship (AMS) strategies worldwide focus on optimised antibiotic use. Selective susceptibility reporting is recommended as an effective AMS tool, although there is a lack of representative studies investigating the impact of selective susceptibility reporting on antibiotic use.The aim of this study was to investigate the impact of selective susceptibility reporting of Staphylococcus aureus (S. aureus) on antibiotic consumption. Enhancing the use of narrow-spectrum beta-lactam antibiotics such as flucloxacillin/cefazolin/cefalexin is one of the main goals in optimising antibiotic therapy of S. aureus infections.Methods:This interventional study with control group was conducted at a tertiary care hospital in Germany. During the one-year interventional period, susceptibility reports for all methicillin-sensitive S. aureus (MSSA) were restricted to flucloxacillin/cefazolin/oral cefalexin, trimethoprim-sulfamethoxazole, clindamycin, gentamicin and rifampin/fosfomycin; instead of reporting all tested antibiotics during the year before the intervention and in the reference clinic. The impact of the intervention was analysed by monitoring antibiotic consumption (recommended daily dose/100 occupied bed days: RDD/100 BD).Results:MSSA-antibiograms were reported for 2836 patients. Total use of narrow-spectrum beta-lactams more than doubled during the intervention (from 1.2 to 2.8 RDD/100 BD, P<0.001; P<0.001 compared to the reference clinic); the percentage of total antibiotic use increased from 2.6% to 6.2%. A slight, but significant increase in the use of trimethoprim-sulfamethoxazole was also observed (+ 0.37 RDD/100 BD).There was no decrease in antibiotics withdrawn from the antibiogram, probably as a consequence of their wide use for indications other than S. aureus infections.Conclusions:As narrow-spectrum beta-lactams are not widely used for other infections, there is a strong indication that selective reporting guided clinicians to optimised antibiotic therapy of S. aureus infections.As useful AMS tool, we recommend implementing selective reporting rules into the national/international standards for susceptibility reporting.