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.

The lack of reliable diagnostic tests for detecting vaccine serotype pneumococcal pneumonia (VTPP) remains a challenging issue in pneumococcal vaccine studies. This study assessed the performances of high-throughput nanofluidic PCR-based pneumococcal serotyping and quantification assay methods using sputum samples (the nanofluidic sputum quantitative PCR [Sp-qPCR] assay) to diagnose 13-valent pneumococcal conjugate VTPP compared with the performance of the serotype-specific urinary antigen detection (UAD) assay using urine samples. Adult pneumonia patients from Japan were enrolled in this study between September 2012 and August 2014. Sputum samples were subjected to the nanofluidic Sp-qPCR assay, quantitatively cultured, and serotyped by the Quellung reaction (SpQt). Urine samples were tested by the UAD method. The diagnostic performances of these tests were assessed using composite reference standards and Bayesian latent class models (BLCMs). Among 244 total patients, 27 (11.1%) tested positive with the UAD assay, while 16 (6.6%) and 34 (13.9%) tested positive with the SpQt and nanofluidic Sp-qPCR assays, respectively, with a cutoff value of ≥104 DNA copies/ml, which showed the maximum value of the Youden index. Using BLCMs, the estimated prevalence for VTPP was 12.9%, and the nanofluidic Sp-qPCR assay demonstrated the best performance (sensitivity, 90.2%; specificity, 96.9%), followed by UAD (sensitivity, 75.6%; specificity, 97.9%) and SpQt (sensitivity, 45.8%; specificity, 99.5%). However, when a higher cutoff value of ≥107 DNA copies/ml was applied, the performance of UAD became comparable to that of Sp-qPCR. The vaccine serotype-specific pneumococcal DNA load in sputum among UAD-positive patients was 3 logs higher than that among UAD-negative patients (P = 0.036). The nanofluidic Sp-qPCR assay may be accurate and useful for detecting VTPP among adults.

Lung abscess is usually treated with long-term antibiotic therapy. Due to the lack of a safe and easy drainage technique, drainage is only applied in refractory cases. We herein describe three cases in which drainage was successfully performed by endobronchial ultrasonography using a modified guide sheath. This procedure may have advantages in the detection of causative pathogens and early infection source control, and may therefore lead to the appropriate selection of antibiotics and reduce the duration of antibiotic therapy.