Racial and ethnic differences in diabetes treatment and outcomes in US hemodialys

描述(申请人提供)：在血液透析(HD)合并糖尿病(DM)的患者中，发生糖尿病相关并发症和死亡率的风险很高。然而，关于糖尿病HD患者的糖尿病控制、治疗和糖尿病相关并发症之间的关系的数据极其有限。此外，这些关系中的种族和族裔差异没有记录在案。目的：这项观察性研究的目的是评估糖尿病血液透析患者血糖控制、口服降糖药物(OAD)治疗以及心血管和非心血管结局之间的关系。我们还将探讨这些关联中的种族和民族差异。方法：我们将使用来自美国肾脏数据系统的数据和DaVita，Inc.的电子医疗记录，对一家大型国家糖尿病供应商的HD合并糖尿病患者进行回顾性队列研究。 透析服务，以检查HbA1c和各种临床结果之间的联系(具体目标1和2)。这些患者中的一个子集将用于对接受TZD或磺脲类单一疗法(特定目标3)的患者进行比较有效性研究。对于前两个目标，我们将使用COX比例风险模型来评估HbA1c和时间与感兴趣的主要结果之间的关联，并通过以下方式测试种族和民族的影响修改 包括交互术语和执行Wald测试。我们将在找到有意义的互动术语后，进一步探索不同种族和民族之间的对比。对于特定的 目的3，我们将比较TZDS的流行和偶发使用者与磺脲类药物的使用者，将所有分析限制在接受这两类药物中的一种单一治疗的患者。我们将通过使用线性回归模型和稳健的三明治估计器进行重复测量分析，来检验OAD单一疗法(TZD与磺脲类药物)和HbA1c之间的关联。我们还将使用COX比例风险模型分析OAD单一疗法(TZD与磺脲类药物)与心血管事件和死亡的时间之间的关系。除了其他敏感性分析外，我们还将进一步进行AS治疗和意向治疗分析，并采用先进的统计方法，包括倾向评分技术。将使用上述方法调查这些联系中的种族和族裔差异，以实现前两个目标。意义：这项研究将利用异常庞大和详细的HD患者数据集。由于有关糖尿病管理和治疗(包括血糖控制和OAD治疗)与糖尿病并发症之间关系的数据有限，因此有必要在这一高危人群中进行更多的研究。此外，我们的研究将有能力调查这些关联中的种族和民族差异，因为我们利用了可供分析的庞大数据库。

DESCRIPTION (provided by applicant): In hemodialysis (HD) patients with diabetes mellitus (DM), the risk of developing diabetes- related complications and mortality is high. However, data on the associations among diabetes control, treatment, and diabetes-related complications in HD patients with DM are extremely limited. In addition, racial and ethnic differences in these relationships have not been documented. Objectives: The objective of this observational study is to assess the relationship among glycemic control, oral antidiabetic drug (OAD) therapy, and both cardiovascular and non-cardiovascular outcomes in HD patients with DM. We will also explore racial and ethnic differences in these associations. Methods: We will use data from the U.S. Renal Data System and electronic medical records of DaVita, Inc., to conduct a retrospective cohort study of patients on HD with diabetes mellitus at a large national provider of dialysis services to examine the associations among HbA1c and various clinical outcomes (Specific Aims 1 and 2). A subset of these patients will be used for a comparative effectiveness study of patients receiving TZD or sulfonylurea monotherapy (Specific Aim 3). For the first two aims, we will use Cox proportional hazards models to assess the associations between HbA1c and time to primary outcomes of interest, and test for effect modification by race and ethnicity by including interaction terms and performing a Wald test. We will further explore contrasts between different racial and ethnic groups upon finding significant interaction terms. For Specific Aim 3, we will compare prevalent and incident users of TZDs to users of sulfonylureas by limiting all analyses to patients receiving monotherapy with one of these two drug classes. We will examine the association between OAD monotherapy (TZD vs. sulfonylurea) and HbA1c by performing a repeated-measures analysis using linear regression models with a robust sandwich estimator. We will also analyze the association between OAD monotherapy (TZD vs. sulfonylurea) and time to cardiovascular events and death using Cox proportional hazards models. We will further conduct as-treated and intention-to-treat analyses in addition to other sensitivity analyses, and employ advanced statistical methods including propensity score techniques. Racial and ethnic differences in these associations will be investigated using the method described above for the first two aims. Significance: This research study will take advantage of an unusually large and detailed dataset of patients initiating HD. Due to the limited data on the associations among diabetes management and treatment, including glycemic control and OAD therapy, and diabetes complications in HD patients with DM, additional studies are warranted in this high-risk population. Moreover, our study will have the ability to investigat racial and ethnic differences in these associations as we capitalize on the enormous size of the database that will be available for analysis.