2021 年 4 月 2 日受付・2021 年 12 月 23 日受理) 要 旨 板橋中央総合病院(以下，当院)は，2018 年の 4 月の診療報酬改定で新設された抗菌薬適正使 用支援加算後の 2018 年 5 月から ASP を導入した．抗菌薬適正使用支援プログラム(antimicrobial stewardship program：ASP)は多くの施設で導入され，広域抗菌薬の使用量減少や薬剤感受性率 回復の報告がされている．本研究では，診療報酬改定を契機に抗菌薬適正使用支援チーム(antimicrobial stewardship team：AST)を組織した市中病院の ASP 導入による効果を検証するため，当 院採用の抗緑膿菌活性のある抗菌薬の使用量を主要評価項目，緑膿菌の薬剤感受性の変化と Clostridioides difficile 感染症(CDI)発生率，経済的効果，AST による介入症例の受諾率を副次評価 項目として後ろ向き調査を実施した．ASP 導入後に注射抗菌剤の薬剤費の減少とカルバペネム系 抗菌薬の使用量を半減することができた．

Limited data are available regarding part-time infectious disease consultations (IDCs) and their importance in tertiary care teaching hospitals in Japan. This is a retrospective review of IDCs from June 2016 to March 2021 and describes IDC services provided by part-time infectious disease specialists once a week for 4 hours, and their impact on the quality of medical care, including antimicrobial stewardship. Data, such as the requesting department, requesting reasons, and final diagnoses, were analyzed. In April 2018, part-time infectious disease specialists launched consultation services and attended an antimicrobial stewardship team conference. Meropenem, tazobactam/piperacillin, and cefepime monthly days of therapy (DOT) were calculated to assess the effect of each intervention; a pre-post analysis was conducted using the Kruskal-Wallis test. Additional quality improvement (QI) projects related to infectious diseases were implemented. There were 237 IDCs during the study period. Consultations were mostly requested by the General Internal Medicine, Emergency Medicine, and Cardiology departments. The most common diagnoses were bone/joint, respiratory, and genitourinary infections. Infectious disease services, even on a part-time basis, achieve good outcomes in patient management, antimicrobial stewardship, and QI projects.DOT/1000 patient-days were reduced for meropenem and cefepime, while it increased for tazobactam/piperacillin. The DOT/1000 patient-days for the 3-antipseudomonal agents significantly decreased during this period. After implementing the QI tetanus vaccination project in the Emergency Room, the number of tetanus toxoid vaccinations per month increased.

Antibiotic stewardship programs reduce antibiotic use without negative clinical outcomes. However, epidemiological data describing the relationship between implementing antimicrobial stewardship and candidemia incidence are scarce. This study aimed to evaluate the effect of antibiotic stewardship on the incidence of hospital acquired candidemia. We conducted a retrospective study from April 2017 to September 2020. We reviewed patients that were treated with three broad-spectrum antipseudomonal agents: carbapenem, tazobactam/piperacillin, and cefepime. Monthly aggregated hospital antimicrobial consumption was measured as days of therapy (DOTs) per 1000 patient-days, and the monthly incidence of hospital acquired candidemia was recorded. The median monthly carbapenem-DOTs during pre-intervention and intervention were 28.4 and 10.0, respectively. Time-series analysis showed significant level changes after intervention: − 10.0 DOTs (p = 0.02). There was a downward trend in the monthly carbapenem-DOTs after intervention. The median hospital-acquired candidemia incidence was 0.17 and 0.08 per 1000 patient-days during pre-intervention and intervention periods, respectively. Time-series analysis showed a significant level change after intervention (− 0.16 per 1000 patient-days; p = 0.048). The trend in the incidence of hospital-acquired candidemia did not significantly change between pre-intervention and intervention. Decreased broad-spectrum antibiotic use (particularly carbapenem) by our antimicrobial stewardship term may reduce hospital-acquired candidemia incidences.