Department of Biostatistics, Erasmus Medical Center, Dr Molewaterplein50, Rotterdam, Netherlands.
Stat Med. 2009 Dec 10;28(28):3470-82. doi: 10.1002/sim.3634.
The split-mouth design is a popular design in oral health research. In the most common split-mouth study, each of two treatments are randomly assigned to either the right or left halves of the dentition. The attractiveness of the design is that it removes a lot of inter-individual variability from the estimates of the treatment effect. However, already about 20 years ago the pitfalls of the design have been reported in the oral health literature. Yet, many clinicians are not aware of the potential problems with the split-mouth design. Further, it is our experience that most statisticians are not even aware of the existence of this design. Since most of the critical remarks appeared in the oral health literature, we argue that it is necessary to introduce the split-mouth design to a statistical audience, so that both clinicians and statisticians clearly understand the advantages, limitations, statistical considerations, and implications of its use in clinical trials and advise them on its use in practice.
分口设计是口腔健康研究中一种常用的设计。在最常见的分口研究中，两种治疗方法中的每一种都被随机分配到牙齿的右侧或左侧。这种设计的吸引力在于，它可以减少个体间变异性对治疗效果估计的影响。然而，大约 20 年前，这种设计的缺陷就已经在口腔健康文献中被报道了。然而，许多临床医生并没有意识到分口设计可能存在的问题。此外，我们的经验是，大多数统计学家甚至不知道这种设计的存在。由于大多数关键评论都出现在口腔健康文献中，我们认为有必要向统计学家介绍分口设计，以便临床医生和统计学家都清楚地了解其在临床试验中的优点、局限性、统计考虑因素和应用意义，并就其在实践中的应用为他们提供建议。
