政策制定者需要对适用于感兴趣人群的相对有效性进行估计,但关于评估和扩展基于随机对照试验(RCT)的评价的普遍性的定量方法的研究很少.我们说明了一种使用观测数据的方法。
我们的例子是全系统演示器(WSD)试验,其中3230名患有慢性病的成年人被分配接受远程医疗或常规护理。首先,我们使用新的安慰剂试验来评估RCT对照组和匹配的接受常规治疗的非参与者亚组之间的结局是否相似.我们匹配了从电子病历中获得的65个基线变量。第二,我们进行了敏感性分析,以考虑对治疗有效性的估计是否符合关于“常规治疗”是否由RCT对照组或非参与者定义的替代假设.因此,我们通过对比RCT远程健康组和匹配的非参与者的结局,提供了相对有效性的替代估计.
对于某些端点,例如门诊就诊人数,安慰剂测试通过了,和有效性估计是稳健的选择比较组。然而,对于其他端点,比如紧急入院,安慰剂试验失败,根据远程健康患者是否与RCT对照组或匹配的非参与者进行比较,治疗效果的估计值存在显著差异.
拟议的安慰剂测试表明,当RCT的估计不能推广到常规临床实践中,并使用观察数据对比较有效性进行补充估计时,这些情况。建议将来的RCT纳入这些安慰剂测试和随附的敏感性分析,以增强其与政策制定的相关性。
Policy makers require estimates of comparative effectiveness that apply to the population of interest, but there has been little research on quantitative approaches to assess and extend the generalizability of randomized controlled trial (RCT)-based evaluations. We illustrate an approach using observational data.
Our example is the Whole Systems Demonstrator (WSD) trial, in which 3230 adults with chronic conditions were assigned to receive telehealth or usual care. First, we used novel placebo tests to assess whether outcomes were similar between the RCT control group and a matched subset of nonparticipants who received usual care. We matched on 65 baseline variables obtained from the electronic medical record. Second, we conducted sensitivity analysis to consider whether the estimates of treatment effectiveness were robust to alternative assumptions about whether \"usual care\" is defined by the RCT control group or nonparticipants. Thus, we provided alternative estimates of comparative effectiveness by contrasting the outcomes of the RCT telehealth group and matched nonparticipants.
For some endpoints, such as the number of outpatient attendances, the placebo tests passed, and the effectiveness estimates were robust to the choice of comparison group. However, for other endpoints, such as emergency admissions, the placebo tests failed and the estimates of treatment effect differed markedly according to whether telehealth patients were compared with RCT controls or matched nonparticipants.
The proposed placebo tests indicate those cases when estimates from RCTs do not generalize to routine clinical practice and motivate complementary estimates of comparative effectiveness that use observational data. Future RCTs are recommended to incorporate these placebo tests and the accompanying sensitivity analyses to enhance their relevance to policy making.