使用综合索赔数据库调查日本乳腺癌患者围绕临床事件的阿片类药物处方状况。这是一项使用国家数据库（2009 年 4 月至 2020 年 3 月）的回顾性队列研究。目标患者在 2010 年 4 月或之后首次诊断出乳腺癌。按月份以及临床设施特征和地点对当月手术前后、骨转移前后以及死亡前诊断为乳腺癌的患者开出阿片类药物的百分比进行了分析。我们确定了 1 085 388 名目标患者，包括分别有 216~503、72~645 和 70~832 名患者的手术、骨转移和死亡事件数据。在手术当月服用阿片类药物的患者比例是整个研究期间最高的，≥70%。服用阿片类药物的患者比例在骨转移前增加，1个月后达到峰值，此后下降，但仍高于事件前。死亡前服用阿片类药物的患者比例随着时间的推移而增加，在死亡前 1 个月达到峰值 33.4%。处方因手术设施特征和设施位置而异；与其他活动相比，设施特征（包括位置）没有差异。在所有事件中，开出阿片类药物的患者比例始终低于其他国家报告的比例。我们显示了日本乳腺癌患者中临床事件的阿片类药物处方状态，包括一些取决于手术前后的设施特征的不同模式.© 作者 2024。由牛津大学出版社出版。

To investigate the opioid prescription status around clinical events among patients with breast cancer in Japan using a comprehensive claims database.This was a retrospective cohort study using the National Database (April 2009-March 2020). The target patients had a first breast cancer diagnosis in April 2010 or later. The percentages of patients prescribed opioids before and after surgery, before and after bone metastasis, and before death with a breast cancer diagnosis in the same month were analyzed by month and by clinical facility characteristics and location.We identified 1 085 388 target patients, including 216 503, 72 645, and 70 832 patients with data for the events of surgery, bone metastasis, and death, respectively. The percentage of patients prescribed opioids in the month of surgery was the highest of the entire study period at ≥70%. The percentage of patients prescribed opioids increased before bone metastasis, peaked 1 month later, and decreased thereafter while remaining higher than that before the event. The percentage of patients who were prescribed opioids before death increased over time, peaking at 33.4% 1 month before death. Prescriptions differed by facility characteristics and facility location around surgery; no differences by facility characteristics, including location, were noted around the other events. The percentage of patients prescribed opioids was consistently lower than that reported in other countries for all events.We showed the opioid prescription status around clinical events, including some distinct patterns depending on facility characteristics for the period around surgery, among patients with breast cancer in Japan.© The Author(s) 2024. Published by Oxford University Press.