Conceptualization, M.M.; methodology, M.M. and K.Y. (Kozue Yamaguchi); validation, M.N., Y.N. and I.T.; formal analysis, M.M., K.Y. (Kaho Yamada) and R.K.; investigation, M.N., Y.N., T.T. and R.O.; resources, M.N. and Y.N.; data curation, M.M.; writing—original draft preparation, M.M.; writing—review and editing, M.N. and Y.N.; visualization, M.M. and K.Y. (Kozue Yamaguchi); supervision, I.T.; project administration, M.M. All authors have read and agreed to the published version of the manuscript.

Figure 1. Monthly DASC and DASC/patient trends during this 2-year period. DASC, days of antibiotic spectrum coverage.

Figure 1. Monthly DASC and DASC/patient trends during this 2-year period. DASC, days of antibiotic spectrum coverage.

Figure 2. Monthly DOT and DOT/patient trends during this 2-year period. DOT, days of therapy.

Figure 2. Monthly DOT and DOT/patient trends during this 2-year period. DOT, days of therapy.

Figure 3. Monthly DASC/DOT trend during this 2-year period. DASC, days of antibiotic spectrum coverage; DOT, days of therapy.

Figure 3. Monthly DASC/DOT trend during this 2-year period. DASC, days of antibiotic spectrum coverage; DOT, days of therapy.

Figure 4. The scatterplot among DASC, DASC/patient, DOT, DOT/patient, DASC/DOT, and the number of patients per month. The x- and y-axes indicate each metric, while the plots indicate each month’s observed values. Diagonal cells show Spearman’s correlation analysis results. A strong correlation was observed between DASC and DOT (ρ = 0.963) as well as DASC/patient and DOT/patient (ρ = 0.923). In contrast, DASC/DOT had no correlation with other metrics (ρ = −0.279–0.368). DASC, days of antibiotic spectrum coverage; DOT, days of therapy.

Figure 4. The scatterplot among DASC, DASC/patient, DOT, DOT/patient, DASC/DOT, and the number of patients per month. The x- and y-axes indicate each metric, while the plots indicate each month’s observed values. Diagonal cells show Spearman’s correlation analysis results. A strong correlation was observed between DASC and DOT (ρ = 0.963) as well as DASC/patient and DOT/patient (ρ = 0.923). In contrast, DASC/DOT had no correlation with other metrics (ρ = −0.279–0.368). DASC, days of antibiotic spectrum coverage; DOT, days of therapy.

Figure 5. The DASC/patient distribution stratified by BSI pathogens. DASC, days of antibiotic spectrum coverage; BSI, bloodstream infection; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; ESBL, extended-spectrum beta-lactamase; AMR, antimicrobial resistance.

Figure 5. The DASC/patient distribution stratified by BSI pathogens. DASC, days of antibiotic spectrum coverage; BSI, bloodstream infection; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; ESBL, extended-spectrum beta-lactamase; AMR, antimicrobial resistance.

Figure 6. The DOT/patient distribution stratified by BSI pathogens. DOT, days of therapy; BSI, bloodstream infection; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; ESBL, extended-spectrum beta-lactamase; AMR, antimicrobial resistance.

Figure 6. The DOT/patient distribution stratified by BSI pathogens. DOT, days of therapy; BSI, bloodstream infection; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; ESBL, extended-spectrum beta-lactamase; AMR, antimicrobial resistance.

Figure 7. The DASC/DOT distribution stratified by BSI pathogens. DASC, days of antibiotic spectrum coverage; DOT, days of therapy; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; ESBL, extended-spectrum beta-lactamase; AMR, antimicrobial resistance.

Figure 7. The DASC/DOT distribution stratified by BSI pathogens. DASC, days of antibiotic spectrum coverage; DOT, days of therapy; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; ESBL, extended-spectrum beta-lactamase; AMR, antimicrobial resistance.

Table 1. Positive blood culture cases and cases without contamination stratified by age category.

Table 1. Positive blood culture cases and cases without contamination stratified by age category.

Age CategoryNo. of Cases
(All, n = 1443)No. of Cases
(Without Contamination, n = 1178)0–546 (3.2)35 (3.0)6–149 (0.6)8 (0.7)15–49121 (8.4)93 (7.9)50–64232 (16.1)189 (16.0)65–74324 (22.5)264 (22.4)≥75711 (49.3)589 (50.0)

Table 2. The overall DASC and DOT metrics in this study population.

Table 2. The overall DASC and DOT metrics in this study population.

YearDASCDASC/PatientDOTDOT/PatientDASC/DOT2020112,235155.914,40320.07.82021114,391158.214,37519.98.0Total226,626157.128,77819.97.9