Days of Antibiotic Spectrum Coverage: A Novel Metric for Inpatient Antibiotic Consumption

Abstract

Background Days of Therapy (DOT), the most widely used benchmarking metric for antibiotic consumption, may not fully measure stewardship efforts to promote use of narrow-spectrum agents and may inadvertently discourage the use of combination regimens when single-agent alternatives have greater adverse effects. To overcome DOT’s limitations, we developed a novel metric, Days of Antibiotic Spectrum Coverage (DASC), and compared hospitals’ performances using this novel metric with DOT. Methods We evaluated 77 antibiotics in 16 categories of antibacterial activity to develop our spectrum scoring system. DASC was then calculated as cumulative daily spectrum scores. To compare hospital benchmarking using DOT and DASC, we conducted a retrospective cohort study of adult patients admitted to acute care units within the Veterans Health Administration system in 2018. Antibiotic administration data were aggregated to calculate each hospital’s DOT and DASC per 1,000 days present (DP) for ranking. Results The spectrum score for each antibiotic ranged from 2 to 15. There was little correlation between DOT per 1,000 DP and DASC per DOT, indicating that lower antibiotic consumption at a hospital does not necessarily mean more frequent use of narrow-spectrum antibiotics. The differences in each hospital’s ranking between DOT and DASC per 1,000 DP ranged from -29.0% to 25.0%, respectively, with 27 (21.8%) hospitals having differences >10%. Conclusions We propose a novel composite metric for antibiotic stewardship, DASC, that combines consumption and spectrum as a potential replacement for DOT. Further studies are needed to evaluate whether benchmarking using the DASC will improve evaluations of stewardship.

Days of Antibiotic Spectrum Coverage Trends and Assessment in Patients with Bloodstream Infections: A Japanese University Hospital Pilot Study

“…In addition, the correlation analysis showed that DASC/DOT had no correlation with other metrics. DASC/DOT was an independent and robust metric that could evaluate the antibiotic spectrum consistent with the previous study [ 18 ]. However, in the case of empirical therapy using broad-spectrum and stopping antibiotics immediately, DASC/DOT reflects a broad-spectrum antibiotics score.…”

“…Moreover, the calculation process of scoring was complicated [ 21 , 22 ]. DASC was simply based on dichotomous scores for efficacy against microorganisms [ 18 ]. Therefore, the ASC scores list was exhaustive, as well as simple to set up.…”

“…Conversely, a high DASC/DOT was observed in Gram-negative bacteria. Antibiotics that have activity against Gram-negative bacteria typically have high ASC scores [ 18 ]. The metrics stratified by BSI pathogens will clarify the object of ASP interventions.…”

“…Kakiuchi et al developed a novel quantitative metric for antimicrobial consumption with antibiotic spectrum consideration to address the problems of conventional metrics [ 18 ]. The individual antibiotic spectrum coverage (ASC) score and its dosing period are used to calculate the days of antibiotic spectrum coverage (DASC).…”

“…The individual antibiotic spectrum coverage (ASC) score and its dosing period are used to calculate the days of antibiotic spectrum coverage (DASC). DASC can evaluate both overall antibiotic consumption and antibiotic spectrum [ 18 ]. Therefore, we considered that DASC will be suitable for disease or pathogen-specific antimicrobial use evaluation, including a de-escalation strategy [ 17 , 19 ].…”