Comparative Effectiveness of Split-dose Colonoscopy Bowel Preparation Regimens

对退伍军人医疗保健的预期影响：通过确定结肠镜肠道准备方案 这在实际VA实践中是最有效的，并且可以立即在VA范围内实施， 这项研究将最大限度地提高结肠镜检查在降低结直肠癌（CRC）风险方面的效果 在退伍军人中，提高退伍军人的满意度，并降低VA医疗保健成本。背景：CRC是一个领先的 退伍军人癌症相关死亡的原因。结肠镜检查可有效降低结直肠癌的发病率， mortality.然而，不坚持筛查结肠镜检查实质上破坏了这种益处。现有 有证据表明，不愉快的肠道准备是完成结肠镜检查的主要障碍， 病人的观点。肠道准备的味道和体积决定了患者的耐受性， 对制备说明的依从性，这又影响不完整性（例如，取消/不- 显示/重新安排）计划的结肠镜检查率以及完成的有效性 结肠镜检查和病人满意度。目前在美国最常用的两种制剂是 分次给药4L聚乙二醇（PEG）和分次给药2L MiraLAX/Gatorade制剂。当一个高- 理论上，容量方案可能比低容量方案更有效，它可能与低容量方案相关。 在现实世界的实践中的耐受性和依从性。三个小型试验比较了这两种制剂。 然而，来自这些解释性试验的数据不能为政策决策提供信息，因为它们是在 在人工条件下，仅限于狭窄的患者人群，最重要的是， 了解肠道准备对结肠镜检查完成率或有效性的全面影响。解决 这一关键的知识差距，我们提出了一个务实的试验，以确定最佳的分割剂量肠 在普通老百姓中做好准备。目的：比较两者在现实世界中的有效性 在美国最常用的分次剂量结肠镜检查肠道准备方案（即，4L PEG和2L MiraLAX/Gatorade）在计划结肠镜检查完成率、腺瘤检出率 其次是准备质量、取消/未出现率和面向患者的结果（例如，意愿 重复制备）。方法：本研究将是一项实用的随机对照试验， 大型地区退伍军人管理局医疗保健系统中现有的两种肠道准备方案。所有> 18岁的退伍军人 年龄在10岁以上，并且正在接受门诊选择性结肠镜检查的患者是合格的。这场务实的审判将是 在放弃知情同意的情况下进行。在护理点订购结肠镜检查的提供者 将被要求在允许患者入组研究或继续当前研究之间进行选择 在VA电子病历（EMR）订购菜单的背景下，使用标准4L PEG。入组 患者将在护理点通过EMR自动随机分配至两个肠道之一 制备方案，然后将显示分配制备的预填充订单 即时发送给EMR中的提供者进行签名。将收集结局和协变量数据 直接从电子病历中提取主要终点是计划的结肠镜检查的总体完成率， 腺瘤检出率，次要终点为取消/未就诊率、肠道准备质量 和以病人为导向的结果。分析将基于意向治疗。我们还将前瞻性收集 成本数据，以便对两种肠道准备方案进行经济评估。

Anticipated Impacts on Veterans Health Care: by identifying a colonoscopy bowel preparation regimen which is the most effective in real-world VA practice and can be immediately implemented on a VA-wide scale, the proposed study will maximize the effectiveness of colonoscopy in reducing colorectal cancer (CRC) risk among veterans, increase veteran satisfaction, and reduce VA healthcare cost. Background: CRC is a leading cause of cancer-related death among veterans. Colonoscopy can effectively reduce CRC incidence and mortality. However, non-adherence to screening colonoscopy substantially undermines this benefit. Existing evidence indicates that a disagreeable bowel preparation is a leading barrier to completing a colonoscopy from the patients' perspective. The taste and the volume of the bowel preparation determine patient tolerability and compliance to the preparation instructions, which in turn affects the incompletion (e.g., cancellation/no- show/reschedule) rate of scheduled colonoscopies as well as the effectiveness of the completed colonoscopies and patient satisfaction. The two most commonly used preparations currently in the US are the split-dose 4L polyethylene glycol (PEG) and the split-dose 2L MiraLAX/Gatorade preparations. While a high- volume regimen may in theory be more effective than a lower volume one, it may be associated with lower tolerability and adherence in real-world practice. Three small trials have compared these two preparations. However, data from these explanatory trials cannot inform policy decisions because they were conducted under artificial conditions, restricted among narrow patient populations, and most importantly not designed to capture the full impact of bowel preparation on the completion rate or effectiveness of colonoscopy. To address this critical knowledge gap, we are proposing a pragmatic trial to determine the optimal split-dose bowel preparation in the general veteran population. Objectives: to compare the real-world effectiveness of the two most commonly used split-dose colonoscopy bowel preparation regimens in the US (i.e., 4L PEG and 2L MiraLAX/Gatorade) with respect to the completion rate of scheduled colonoscopies, adenoma detection rate and secondarily preparation quality, cancellation/no-show rate and patient-oriented outcomes (e.g., willingness to repeat the preparation). Methods: the study will be a pragmatic randomized controlled trial comparing the two existing bowel preparation regimens in a large regional VA healthcare system. All veterans who are > 18 years of age and undergoing an outpatient elective colonoscopy are eligible. This pragmatic trial will be conducted with a waiver of informed consent. Providers who are ordering a colonoscopy at the point of care will be asked to choose between allowing the patient to be enrolled in the study or continuing with the current standard 4L PEG within the context of the VA electronic medical records (EMR) ordering menu. Enrolled patients will be automatically randomized through the EMR at the point of care to one of the two bowel preparation regimens, and a pre-populated order for the assigned preparation will then be presented instantaneously to the provider in the EMR for signature. Outcomes and covariates data will be collected directly from the EMR. The primary endpoints are overall completion rate of scheduled colonoscopy and adenoma detection rate, and the secondary endpoints are cancellation/no-show rate, bowel preparation quality and patient-oriented outcomes. Analysis will be based on intention-to-treat. We will also prospectively collect cost data in order to perform an economic evaluation of the two bowel preparation options.