IMPROVING THE EVIDENCE FOR UNSTABLE ANGINA GUIDELINES

该项目旨在改善AHCPR不稳定心绞痛实践指南的证据基础，该指南挑战临床医生考虑对具有急性心肌缺血(ACI)症状的低风险患者进行门诊管理。利用ED决策的两个临床有效性试验的资源，即急性心脏缺血时间不敏感预测仪器(ACI-TIPI)Impact试验和即将完成的Sestamibi扫描临床试验，该项目将确定符合指南分类建议是否与降低不良结果(非致命性心肌梗死和死亡)的短期发生率和减少短期利用(ED复诊、再住院、冠状动脉造影术和血管重建)相关。通过图表回顾，我们将根据AHCPR分诊指南和其他不稳定心绞痛风险分层模型，提取必要的项目，根据9191名研究患者的不良短期结果风险对其进行分类。对于每个指南风险组，我们将在分层Logistic回归模型中测试分诊倾向对不良结果预测的独立贡献，控制患者水平、医生水平和医院水平的不良结果预测因素。由于这些预测因子的不平衡分布可能会对“指南-一致性”和“指南-不一致性”分诊处理组的不良结果的比较产生偏差，我们将检查两种病例组合调整方法：倾向评分和ACI-TIPI评分。由于除了指南之外，其他几种现有的工具可能会改善急性心脏护理的决策，我们还将计算指南风险组在区分有和没有不良短期结果的患者方面的敏感性和特异性，并与其他可用的ACI预后模型进行比较。拟议的研究将为政策制定者提供预测指南实施对结果、成本和对出现不稳定心绞痛症状的患者的医疗服务使用的影响的能力。

This project aims to improve the evidence base for the AHCPR Unstable Angina Practice Guideline, which challenges clinicians to consider outpatient management for low-risk patients with symptoms suggestive of acute cardiac ischemia (ACI). Capitalizing on the resources of two clinical effectiveness trials of ED decision making, the Acute Cardiac Ischemia Time Insensitive Predictive Instrument (ACI-TIPI) Impact Trial and the nearly completed Sestamibi Scan Clinical Trial, this project will determine whether agreement with guideline recommendations for triage is associated with decreased short-term rates of adverse outcomes (non-fatal myocardial infarction and death) and decreased short-term utilization (ED revisits, readmissions, coronary angiography, and revascularization). Through chart review, we will abstract items necessary to categorize 9191 study patients according to their risk of adverse short term outcomes, based on AHCPR triage guidelines and other unstable angina risk stratification models. For each guideline risk group, we will test the independent contribution of triage disposition to the prediction of adverse outcomes in hierarchical logistic regression models, controlling for the patient-level, physician-level, and hospital-level predictors of adverse outcomes. As unbalanced distribution of these predictors may bias comparisons of adverse outcome in "guideline- concordant" versus "guideline-discordant" triage disposition groups, we will examine two approaches for case-mix adjustment: propensity scores and ACI-TIPI scores. As several other existing instruments, in addition to guidelines, may improve decision-making in acute cardiac care, we will also compute the sensitivity and specificity of the guideline's risk groups in discriminating between patients with and without adverse short-term outcomes, compared to that of other available prognostic models for ACI. The proposed research will provide policymakers with the ability to project the impact of guideline implementation on outcomes, cost, and the use of health care services for patients with symptoms suggestive of unstable angina.