908 - Evaluation of Blood Culture Submission Rates in Japan

Background: Blood culture tests are useful for accurate diagnosis of bacteremia and selection of antimicrobial treatment, and they are essential for instituting antimicrobial resistance (AMR) countermeasures. This study investigated blood culture submission rates in Japan and their association with the incidence of bloodstream infections.

Methods: Blood culture data recorded in the Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) database from January to December 2019 and data submitted for consecutive 12 months from acute care hospitals (hospitals with a mean length of patient stay of ≤19 days) were included for analysis. Samples comprised 1 set of blood culture samples (aerobic and anaerobic bottles) defined as one submission. The annual blood culture submission rate was calculated as the total number of submitted blood cultures per 1000 patients/day. The incidence of bloodstream infections was calculated as the number of positive blood cultures excluding contaminated specimens per 1000 patients/day. The blood culture submission rate was then divided into four categories, respectively: category 1: 0–15; category 2: 15–30; category 3: 30–45; and category 4: 45–80.
The Kruskal-Wallis test was performed to determine overall difference among 4 submission rate categories and the Dunn test with Bonferroni correction was used to compare pairs of submission rate categories.Filtering of facilities for data analysis


Results: A total of 117 hospitals were included in the analysis. The median number of beds was 415.0 (interquartile ratio [IQR]: 274.5–549.5). The median incidence of bloodstream infection was 2.78 (2.17–3.87). The median blood culture submission rate was 26.18 (17.20–35.76). The median incidence of bloodstream infection by category of blood culture submission rate was 1.39, 2.53, 3.61, and 4.48, respectively; with a significant difference observed among the four categories overall (p< 0.01). Significant differences were observed between categories 1 and 2 and between categories 2 and 3 (both p< 0.01) but not between categories 3 and 4 (p=0.758).Characteristics of the acute hospitals by category of blood culture submission rate
Incidence of bloodstream infections by category of blood culture submission rate


Conclusion: The blood culture submission rate is considered to be around 45 in the acute hospital setting in Japan. The incidence of bloodstream infections is greatly affected by submission rates.