Confounding by contraindication in a nationwide cohort study of risk for death in patients taking ibopamine
Confounding by contraindication in a nationwide cohort study of risk for death in patients taking ibopamine
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DOI：
10.7326/0003-4819-134-7-200104030-00010
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发表时间：
2001-04-03
影响因子：
39.2
通讯作者：
Stricker, BHC
中科院分区：
文献类型：
--
作者：
Feenstra, H;Grobbee, RE;Stricker, BHC
背景资料：治疗和未治疗患者的结果可能不同，因为后者的治疗禁忌症与所关注的结果独立相关。目的：评估禁忌症对1995年9月初异波帕明使用受限后服用异波帕明患者死亡风险因素的混杂效应。设计：回顾性队列研究，设置：荷兰，患者：1146例充血性心力衰竭患者，至少接受过一次异波帕明处方治疗，并且有用药史和医疗数据，测量：心血管风险因素、临床特征和药物使用。每个病人都被分配了一个索引日期（死亡日期，或研究结束时仍然存活的患者的随机日期）。在单变量分析中，比较索引日期在1995年9月8日之前和之后的患者，与当前使用异波帕明相关的死亡相对风险为3.02（95% CI，2.12至4.30）与0.71（CI，0.53至0.96）相比。在多变量分析中，死亡的风险分别为2.62（CI，1.76至3.90）和0.93（CI，0.84至1.02），分别。结论：相对危险度估计的显着反转可以被认为是一个实际的例子混淆禁忌症。
Background: outcomes may differ in treated and untreated patients because of a contraindication for treatment in the latter that is independently associated with the outcome of interest.Objective: To evaluate the effects of confounding by contraindication on risk factors for death in patients taking ibopamine after its use was restricted in early September 1995.Design: Retrospective cohort study,Setting: The Netherlands, Patients: 1146 patients with congestive heart failure who were prescribed ibopamine at least once and for whom medication history and medical data were available,Measurements: Cardiovascular risk factors, clinical characteristics, and medication use. Each patient was assigned an index date (the date of death, or a random date for patients still alive at the end of the study).Results: In univariate analyses comparing patients with an index date before and those with an index date after 8 September 1995, the relative risk for death associated with current use of ibopamine was 3.02 (95% CI, 2.12 to 4.30) compared with 0.71 (CI, 0.53 to 0.96), respectively. In multivariate analyses, the risk for death was 2.62 (CI, 1.76 to 3.90) and 0.93 (CI, 0.84 to 1.02), respectively.Conclusion: The marked inversion of the relative risk estimate can be considered a practical example of confounding by contraindication.