Division of HIV/AIDS Prevention, National Center for HIV, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
AIDS. 2011 Apr 24;25(7):989-96. doi: 10.1097/QAD.0b013e3283467198.
Studies evaluating the efficacy of HIV/AIDS interventions often involve the random assignment of groups of participants or the treatment of participants in groups. These studies require analytic methods that take within-group correlation into account. We reviewed published studies to determine the extent to which within-group correlation was dealt with properly.
We reviewed group-randomized trials (GRTs) and individually randomized group treatment (IRGT) trials published in HIV/AIDS and general public health journals 2005-2009.
At least two of the authors reviewed each article, recording descriptive characteristics, sample size estimation methods, analytic methods, and judgments about whether the methods took intraclass correlation into account properly.
Of those articles including sufficient information to judge whether analytic methods were correct, only 24% used only appropriate methods for dealing with the intraclass correlation. The percentages differed substantially for GRTs (41.7%) and IRGT trials (8.0%). Most of the articles (69.2%) also made no mention of a priori sample size estimation.
A majority of the articles in our review reported analyses ignoring the intraclass correlation. This practice may result in underestimated variance, inappropriately small P values, and incorrect conclusions about the effectiveness of interventions. Previous trials that were analyzed incorrectly need to be re-analyzed, and future trials should be designed and analyzed with appropriate methods. Also, journal reviewers and editors need to be aware of the special requirements for design and analysis of GRTs and IRGT trials and judge the quality of articles reporting on such trials according to appropriate standards.
评估 HIV/AIDS 干预措施效果的研究通常涉及将参与者分组进行随机分配或对组内的参与者进行分组治疗。这些研究需要考虑组内相关性的分析方法。我们回顾了已发表的研究，以确定适当处理组内相关性的程度。
我们回顾了 2005-2009 年在 HIV/AIDS 和一般公共卫生期刊上发表的群组随机试验（GRT）和个体随机分组治疗（IRGT）试验。
至少有两名作者审查了每篇文章，记录描述性特征、样本量估计方法、分析方法以及关于方法是否正确考虑组内相关的判断。
在那些包括足够信息以判断分析方法是否正确的文章中，只有 24%仅使用了适当的方法来处理组内相关。GRT（41.7%）和 IRGT 试验（8.0%）的百分比差异很大。大多数文章（69.2%）也没有提及事先的样本量估计。
我们综述中的大多数文章报告的分析忽略了组内相关性。这种做法可能导致低估方差、不适当的小 P 值以及对干预效果的错误结论。之前分析不正确的试验需要重新分析，未来的试验应设计和分析采用适当的方法。此外，期刊审稿人和编辑需要意识到 GRT 和 IRGT 试验的设计和分析的特殊要求，并根据适当的标准判断报告此类试验的文章的质量。
