Pairman Lorna, Beh Yong Tai, Maher Hannah, Gardiner Sharon J, Chin Paul, Williman Jonathan, Chambers Stephen T
Department of Medicine, University of Otago Christchurch, 2 Riccarton Avenue, Christchurch, New Zealand.
Department of General Medicine, Te Whatu Ora Health NZ-Waitaha Canterbury, Christchurch Hospital, 2 Riccarton Avenue, Christchurch, New Zealand.
J Antimicrob Chemother. 2025 May 2;80(5):1354-1361. doi: 10.1093/jac/dkaf081.
Legionnaires' disease (LD) is typically treated with macrolides, including the azalide azithromycin, or quinolones. In 2013, guidelines for empirical treatment of community-acquired pneumonia at Christchurch Hospital, New Zealand were changed to prioritize oral azithromycin over IV clarithromycin.
To determine whether the change in antimicrobial guidelines led to altered outcomes for patients subsequently confirmed to have LD.
Patients with confirmed LD between 2010 and 2020 were identified from clinical and laboratory data. Hospital records were used to identify mortality, ICU admission, length of hospital stay, time to clinical stability, and time to first anti-Legionella treatment. Mean differences, risk ratios (RRs) and an interrupted time series with propensity adjustment were used to compare patient outcomes before and after the guideline change.
There were 323 patients included: 128 before and 195 after the change. Patient outcomes generally improved after the change including: mortality within 30 days (RR 0.4, 95% CI 0.2-0.8); ICU admission (RR 0.6, 95% CI 0.5-0.9); length of stay (difference -2.3 days, 95% CI -4.3 to -0.4); and time to clinical stability (difference -2.4 days, 95% CI -4.3 to -0.5). The interrupted time series analysis suggested improvements in patient outcomes may have occurred regardless of the guideline change.
Outcomes for patients with LD were not worsened by the change in antimicrobial guidelines and may have improved. Overall rates of mortality were low. This result was reassuring given the harm that may result from unnecessary use of IV compared with oral antimicrobial agents.
军团菌病（LD）通常用大环内酯类药物治疗，包括氮杂内酯类阿奇霉素，或喹诺酮类药物。2013年，新西兰克赖斯特彻奇医院社区获得性肺炎经验性治疗指南发生了变化，将口服阿奇霉素置于静脉注射克拉霉素之前优先使用。
确定抗菌药物指南的改变是否导致随后确诊为LD的患者的治疗结果发生变化。
从临床和实验室数据中识别出2010年至2020年期间确诊为LD的患者。利用医院记录确定死亡率、入住重症监护病房（ICU）情况、住院时间、临床稳定时间以及首次抗军团菌治疗时间。采用平均差异、风险比（RRs）以及倾向调整的中断时间序列来比较指南改变前后的患者治疗结果。
共纳入323例患者，其中指南改变前128例，改变后195例。指南改变后患者的治疗结果总体有所改善，包括：30天内死亡率（RR 0.4，95%置信区间0.2 - 0.8）；入住ICU情况（RR 0.6，95%置信区间0.5 - 0.9）；住院时间（差异 -2.3天，95%置信区间 -4.3至 -0.4）；以及临床稳定时间（差异 -2.4天，95%置信区间 -4.3至 -0.5）。中断时间序列分析表明，无论指南是否改变，患者的治疗结果可能都有所改善。
抗菌药物指南的改变并未使LD患者的治疗结果恶化，反而可能有所改善。总体死亡率较低。鉴于与口服抗菌药物相比，静脉注射抗菌药物的不必要使用可能带来危害，这一结果令人安心。
