OBJECTIVES We aimed to study whether national and local antibiotic stewardship projects have reduced the antibiotic use in newborns and to monitor potential changes in adverse outcomes. METHODS In a nationwide, population-based study from Norway, we included all hospital live births from 34 weeks' gestation (n = 282 046) during 2015 to 2019. The primary outcome was the proportion of newborns treated with antibiotics from 0 to 28 days after birth. The secondary outcomes were the overall duration of antibiotic treatment and by categories: culture-positive sepsis, clinical sepsis, and no sepsis. RESULTS A total of 7365 (2.6%) newborns received intravenous antibiotics during the period, with a reduction from 3.1% in 2015 to 2.2% in 2019 (30% decrease; P < .001). Hospitals with antibiotic stewardship projects experienced the largest reduction (48% vs 23%; P < .001). We found a small decrease in the median duration of antibiotic treatment in newborns without sepsis from 2.93 to 2.66 days (P = .011), and geographical variation was reduced during the study period. The overall number of days with antibiotic treatments was reduced by 37% from 2015 to 2019 (119.1 of 1000 vs 75.6 of 1000; P < .001). Sepsis was confirmed by blood culture in 206 newborns (incidence rate: 0.73 cases per 1000 live births). We found no increase in sepsis with treatment onset >72 hours of life, and sepsis-attributable deaths remained at a low level. CONCLUSIONS During the study period, a substantial decrease in the proportion of newborns treated with antibiotics was observed together with a decline in treatment duration for newborns without culture-positive sepsis.

中文翻译：

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足月和近期新生儿的抗生素使用。

目的 我们旨在研究国家和地方抗生素管理项目是否减少了新生儿抗生素的使用，并监测不良结局的潜在变化。方法 在挪威的一项全国性、基于人群的研究中，我们纳入了 2015 年至 2019 年期间妊娠 34 周（n = 282 046）的所有住院活产婴儿。主要结果是新生儿在 0 至 28 天期间接受抗生素治疗的比例出生后。次要结果是抗生素治疗的总持续时间和分类：培养阳性败血症、临床败血症和无败血症。结果 在此期间，共有 7365 名（2.6%）新生儿接受了静脉抗生素治疗，从 2015 年的 3.1% 下降到 2019 年的 2.2%（下降 30%；P < .001）。拥有抗生素管理项目的医院减少幅度最大（48% 对 23%；P < .001）。我们发现没有脓毒症的新生儿抗生素治疗的中位持续时间从 2.93 天减少到 2.66 天 (P = .011)，并且在研究期间地域差异有所减少。从 2015 年到 2019 年，抗生素治疗的总天数减少了 37%（1000 人中的 119.1 天对 1000 人中的 75.6 天；P < .001）。206 名新生儿经血培养证实败血症（发病率：0.73 例/1000 例活产）。我们发现治疗开始时间超过 72 小时的脓毒症没有增加，脓毒症导致的死亡人数保持在较低水平。结论 在研究期间，