Statistical power of negative randomized controlled trials presented at American Society for Clinical Oncology annual meetings
Statistical power of negative randomized controlled trials presented at American Society for Clinical Oncology annual meetings
复制标题
DOI：
10.1200/jco.2007.11.3670
复制
发表时间：
2007-08-10
影响因子：
45.3
通讯作者：
Tannock, Ian F.
中科院分区：
文献类型：
--
作者：
Bedard, Philippe L.;Krzyzanowska, Monika K.;Tannock, Ian F.
目的调查美国临床肿瘤学会(ASCO)年会上发表的低效随机对照试验(RCT)的发生率。方法我们调查了1995年至2003年ASCO年会上发表的所有双臂III期随机对照试验。使用80%的功率和0.05的阿尔法水平(双面)进行后期计算，以确定检测小、中、大效果尺寸所需的样本大小。对于报告比例或事件发生时间作为主要终点的研究，效应大小分别用优势比(OR)或风险比(HR)表示，其中小效应大小定义为OR/HR&>=1.3，中等效应大小定义为OR/HR&>1.5，大效应大小定义为OR/HR&>=2.0。结果423例阴性随机对照试验中，45例(10.6%)、138例(32.6%)和233例(55.1%)样本容量分别足以检测小、中、大效应大小。只有35项随机对照试验(7.1%)报告了样本量不足的原因。在多变量模型中，在口头会议上发表的研究(P
Purpose To investigate the prevalence of underpowered randomized controlled trials (RCTs) presented at American Society of Clinical Oncology (ASCO) annual meetings.Methods We surveyed all two- arm phase III RCTs presented at ASCO annual meetings from 1995 to 2003 for which negative results were obtained. Post hoc calculations were performed using a power of 80% and an alpha level of .05 (two sided) to determine sample sizes required to detect small, medium, and large effect sizes. For studies reporting a proportion or time-to-event as primary end point, effect size was expressed as an odds ratio (OR) or hazard ratio (HR), respectively, with a small effect size defined as OR/ HR >= 1.3, medium effect size defined as OR/ HR >= 1.5, and large effect size defined as OR/ HR >= 2.0. Logistic regression was used to identify factors associated with lack of statistical power.Results Of 423 negative RCTs for which post hoc sample size calculations could be performed, 45 (10.6%), 138 ( 32.6%), and 233 (55.1%) had adequate sample size to detect small, medium, and large effect sizes, respectively. Only 35 negative RCTs (7.1%) reported a reason for inadequate sample size. In a multivariable model, studies that were presented at oral sessions (P