Private Practice, Plano, TX.
Graduate Prosthodontics, Texas A&M College of Dentistry, Dallas, TX.
J Prosthodont. 2019 Feb;28(2):159-162. doi: 10.1111/jopr.13010. Epub 2019 Jan 8.
An important consideration in the proper planning of randomized controlled trials (RCTs) is the determination of sample size. A study may fail to answer its research question if the sample size is inadequate, while a large enough sample size may be impractical to implement. The purpose of this study is to describe the reporting of sample size methodology and parameters used in RCTs published in prosthodontic journals.
A MEDLINE search for publications categorized as RCTs was conducted for articles in The Journal of Prosthodontics and The Journal of Prosthetic Dentistry published from 2008 to 2017. The Abstract and Methodology sections of RCTs identified were reviewed, and the following data recorded: reporting of method used to calculate sample size and reporting of parameters used for sample size calculation - type I error (α), type II error (β) or power, minimal clinically relevant difference (MCRD), and variability.
The search strategy retrieved 96 articles; 42 met inclusion criteria for RCTs and were reviewed. Fifty percent (21) of RCTs reported how sample size was determined, but only 17% (7) of RCTs reported all 4 parameters. Type I error (α) was reported in 90% (38) of RCTs, 38% (16) reported power, while only 26% (11) and 12% (5) reported MCRD and variability, respectively.
Methodology and parameters used for sample size determination are inadequately reported in RCTs published in prosthodontic journals.
在正确规划随机对照试验 (RCT) 时，一个重要的考虑因素是确定样本量。如果样本量不足，研究可能无法回答其研究问题，而足够大的样本量可能难以实施。本研究的目的是描述发表在修复期刊中的 RCT 中样本量方法和参数的报告情况。
对 2008 年至 2017 年期间发表在《修复学杂志》和《修复牙科杂志》上的分类为 RCT 的出版物进行了 MEDLINE 搜索。对识别出的 RCT 的摘要和方法部分进行了审查，并记录了以下数据：报告用于计算样本量的方法以及用于样本量计算的参数报告 - Ⅰ型错误（α）、Ⅱ型错误（β）或功效、最小临床相关差异 (MCRD) 和变异性。
搜索策略检索到 96 篇文章；42 篇符合 RCT 的纳入标准并进行了审查。50%（21 篇）的 RCT 报告了如何确定样本量，但只有 17%（7 篇）的 RCT 报告了所有 4 个参数。90%（38 篇）的 RCT 报告了Ⅰ型错误（α），38%（16 篇）报告了功效，而仅 26%（11 篇）和 12%（5 篇）分别报告了 MCRD 和变异性。
发表在修复学杂志上的 RCT 中，样本量确定的方法和参数报告不足。
