引言：癌症登记和医院电子病历常用于研究癌症的药物重用候选者。然而，行政数据通常比癌症登记和医疗记录的数据更易获取。因此，我们评估了行政数据是否可以用于评估癌症的药物重用，通过进行一个关于β受体阻断剂使用与乳腺癌死亡率之间关联的示例研究。方法：我们使用连接的数据集，包括州级住院数据和全国范围内的药物索赔数据，进行了一项针对50岁及以上女性的乳腺癌患者的回顾性队列研究。比较在诊断前和诊断时接受β受体阻断剂和一线降压药的女性。根据常用处方的乳腺癌抗肿瘤药物和住院诊断代码的算法，推断乳腺癌分子亚型和转移状态。针对年龄、查尔逊共病指数、充血性心力衰竭、心肌梗死、分子亚型、诊断时是否存在转移以及乳腺癌手术，使用Fine和Gray的竞争风险模型估计了乳腺癌死亡的亚分布风险比（sHR）和相应的95%置信区间（CI）。结果：共有2,758名住院患有初发乳腺癌的女性。604名接受β受体阻断剂治疗，1,387名接受一线降压药治疗。在中位随访时间为2.7年的过程中，共有154例乳腺癌死亡。我们发现任何β受体阻断剂的使用与乳腺癌死亡之间没有显著的关联（sHR 0.86，95%CI 0.58-1.28），在β受体阻断剂类型分层分析中也没有显著的结果（非选择性：sHR 0.42，95%CI 0.14-1.25；选择性：sHR 0.95，95%CI 0.63-1.43）。在分子亚型分层分析中也没有显著结果（例如，三阴性乳腺癌（TNBC），任何β受体阻断剂，sHR 0.16，95%CI 0.02-1.51）。讨论：可以使用行政数据探索药物重用机会。虽然结果不显著，但对于TNBC亚型发现了一个关联的迹象，这与使用登记数据的先前研究一致。未来需要进行更大样本量、更长随访的研究来证实这种关联，并需要与临床数据源进行链接以验证我们的方法。版权所有 © 2023 Tan、Botteri、Wood、Sloan和Ilomäki。

Introduction: Cancer registries and hospital electronic medical records are commonly used to investigate drug repurposing candidates for cancer. However, administrative data are often more accessible than data from cancer registries and medical records. Therefore, we evaluated if administrative data could be used to evaluate drug repurposing for cancer by conducting an example study on the association between beta-blocker use and breast cancer mortality. Methods: A retrospective cohort study of women aged ≥50 years with incident breast cancer was conducted using a linked dataset with statewide hospital admission data and nationwide medication claims data. Women receiving beta blockers and first-line anti-hypertensives prior to and at diagnosis were compared. Breast cancer molecular subtypes and metastasis status were inferred by algorithms from commonly prescribed breast cancer antineoplastics and hospitalization diagnosis codes, respectively. Subdistribution hazard ratios (sHR) and corresponding 95% confidence intervals (CIs) for breast cancer mortality were estimated using Fine and Gray's competing risk models adjusted for age, Charlson comorbidity index, congestive heart failure, myocardial infraction, molecular subtype, presence of metastasis at diagnosis, and breast cancer surgery. Results: 2,758 women were hospitalized for incident breast cancer. 604 received beta-blockers and 1,387 received first-line antihypertensives. In total, 154 breast cancer deaths were identified over a median follow-up time of 2.7 years. We found no significant association between use of any beta-blocker and breast-cancer mortality (sHR 0.86, 95%CI 0.58-1.28), or when stratified by beta-blocker type (non-selective, sHR 0.42, 95%CI 0.14-1.25; selective, sHR 0.95, 95%CI 0.63-1.43). Results were not significant when stratified by molecular subtypes (e.g., triple negative breast cancer (TNBC), any beta blocker, sHR 0.16, 95%CI 0.02-1.51). Discussion: It is possible to use administrative data to explore drug repurposing opportunities. Although non-significant, an indication of an association was found for the TNBC subtype, which aligns with previous studies using registry data. Future studies with larger sample size, longer follow-up are required to confirm the association, and linkage to clinical data sources are required to validate our methodologies.Copyright © 2023 Tan, Botteri, Wood, Sloan and Ilomäki.