Gail M H, Byar D P, Pechacek T F, Corle D K
Division of Cancer Etiology, National Cancer Institute, Rockville, Maryland 20892.
Control Clin Trials. 1992 Feb;13(1):6-21. doi: 10.1016/0197-2456(92)90026-v.
We present statistical considerations for the design of the Community Intervention Trial for Smoking Cessation (COMMIT). One outcome measurement, the quit rate in randomly selected cohorts of smokers, is compared with another outcome measurement, the decrease in smoking prevalence, in terms of statistical efficiency and interpretability. The COMMIT study uses both types of outcome measurements. The merits of pair-matching the communities are considered, and sample size calculations take into account heterogeneity among pair-matched communities. In addition to significance tests based on the permutational (randomization) distribution, we also describe approaches for covariate adjustment. The COMMIT design includes 11 pair-matched communities, which should provide good power to detect a 10% or greater difference in quit rates between the intervention and control communities in cohorts of heavy smokers and in cohorts of light or moderate smokers. The power is only moderate to detect intervention effects on the decreases in overall smoking prevalence or in the prevalence of heavy smoking.
我们介绍了戒烟社区干预试验（COMMIT）设计中的统计学考量。就统计效率和可解释性而言，将一种结局测量指标（随机选择的吸烟者队列中的戒烟率）与另一种结局测量指标（吸烟流行率的下降）进行了比较。COMMIT研究使用了这两种结局测量指标。考虑了对社区进行配对匹配的优点，样本量计算考虑了配对匹配社区之间的异质性。除了基于排列（随机化）分布的显著性检验外，我们还描述了协变量调整的方法。COMMIT设计包括11个配对匹配的社区，这应为检测重度吸烟者队列以及轻度或中度吸烟者队列中干预社区与对照社区之间戒烟率有10%或更大差异提供足够的检验效能。对于检测干预对总体吸烟流行率下降或重度吸烟流行率下降的影响，检验效能仅为中等。
