分析具有双对照的匹配设计的方法：在评估交通死亡时，很容易估计和误解超额风险。

Methods for analyzing matched designs with double controls: excess risk is easily estimated and misinterpreted when evaluating traffic deaths.

机构信息

Department of Medicine, University of Toronto, Toronto, Ontario M5S 1A1, Canada; Evaluative Clinical Sciences Program, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada; Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada; Division of General Internal Medicine, Sunnybrook Health Science Centre, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Center for Leading Injury Prevention Practice Education & Research, Toronto, Ontario M4N 3M5, Canada.

Department of Biomedical Data Sciences, Stanford University, 450 Serra Mall, Stanford, CA 94305, USA; Department of Statistics, Stanford University, 450 Serra Mall, Stanford, CA 94305, USA.

出版信息

J Clin Epidemiol. 2018 Jun;98:117-122. doi: 10.1016/j.jclinepi.2018.02.005. Epub 2018 Feb 13.

DOI:10.1016/j.jclinepi.2018.02.005

PMID:29452220

Abstract

OBJECTIVES

To demonstrate analytic approaches for matched studies where two controls are linked to each case and events are accumulating counts rather than binary outcomes. A secondary intent is to clarify the distinction between total risk and excess risk (unmatched vs. matched perspectives).

STUDY DESIGN AND SETTING

We review past research testing whether elections can lead to increased traffic risks. The results are reinterpreted by analyzing both the total count of individuals in fatal crashes and the excess count of individuals in fatal crashes, each time accounting for the matched double controls.

RESULTS

Overall, 1,546 individuals were in fatal crashes on the 10 election days (average = 155/d), and 2,593 individuals were in fatal crashes on the 20 control days (average = 130/d). Poisson regression of total counts yielded a relative risk of 1.19 (95% confidence interval: 1.12-1.27). Poisson regression of excess counts yielded a relative risk of 3.22 (95% confidence interval: 2.72-3.80). The discrepancy between analyses of total counts and excess counts replicated with alternative statistical models and was visualized in graphical displays.

CONCLUSION

Available approaches provide methods for analyzing count data in matched designs with double controls and help clarify the distinction between increases in total risk and increases in excess risk.

摘要

目的

展示适用于匹配研究的分析方法，其中每个病例都与两个对照相关联，且事件是累积计数而不是二分类结果。次要目的是澄清总风险和超额风险（非匹配与匹配视角）之间的区别。

研究设计与设置

我们回顾了过去研究选举是否会导致交通风险增加的研究。通过分析致命事故中个体的总计数和致命事故中个体的超额计数，每次都考虑到匹配的双对照，重新解释了结果。

结果

在 10 个选举日，共有 1546 人发生致命事故（平均每天 155 人），在 20 个对照日，共有 2593 人发生致命事故（平均每天 130 人）。对总计数进行泊松回归得到相对风险为 1.19（95%置信区间：1.12-1.27）。对超额计数进行泊松回归得到相对风险为 3.22（95%置信区间：2.72-3.80）。在使用替代统计模型的分析中，总计数和超额计数的分析差异得到了复制，并在图形显示中得到了可视化。