分析固定因素和伴时变量交互作用的三种方法比较

Comparison of Three Approaches in the Analysis of Interaction between a Time-fixed Factor and a Time-varying Variable

目的本文将介绍分析固定因素和伴时变量交互作用的三种方法 :时间序列方法、单纯病例研究法和病例交叉法,并通过模拟研究比较其优劣。方法计算机模拟吸烟和非吸烟人群的日死亡人数时间序列,用三种不同方法分析每日大气可吸入颗粒物(PM10)浓度和吸烟对死亡影响的交互作用,比较各方法的检验效能和误差。结果时间序列方法与单纯病例研究法的检验效能和误差相一致,而病例交叉法的检验效能略低,误差略高于其他两种方法。结论三种方法都是分析固定因素和伴时变量交互作用的有效工具。时间序列方法与单纯病例研究法的表现略佳。

Objective This study aimed at illustrating three approaches for the analysis of interaction between a time-fixed factor and a time-varying variable,including Poisson regression,the case-only approach and case-crossover method.We also compared their statistical performance using a simulation study.Methods Two surrogate time-series of daily counts of mortality for smokers and non-smokers were produced using simulation.We analyzed the interaction between daily concentration of PM10 and smoking using three approaches.Their statistical performances were assessed by power and error.Results The case-only approach had the same performance with Poisson regression. Lower statistical power and bigger error were observed in the results from case-crossover method.Conclusion These three approaches are all useful tool in analysis of interaction between time-fixed factors and time-varying variables.Poisson regression and case-only approach provide better statistical performances.