非平衡而非平衡随机对照试验更常偏向于新治疗方法：一项暴露和未暴露研究。

Unbalanced rather than balanced randomized controlled trials are more often positive in favor of the new treatment: an exposed and nonexposed study.

机构信息

INSERM U 1153, Hôtel-Dieu, 1 place du parvis Notre-Dame, 75004 Paris, France; INSERM CIC 1415, Hôpital Bretonneau, CHRU de Tours, 2 boulevard Tonnellé, 37044 Tours cedex 9, France; Université François-Rabelais de Tours, PRES Centre-Val de Loire Université, 60 rue du Plat d'Etain, 37020 Tours cedex 1, France; Département Universitaire de Médecine Générale, Université François-Rabelais de Tours, PRES Centre-Val de Loire Université, 10 boulevard Tonnellé, BP 3223, 37044 Tours cedex 1, France.

INSERM U 1153, Hôtel-Dieu, 1 place du parvis Notre-Dame, 75004 Paris, France; INSERM CIC 1415, Hôpital Bretonneau, CHRU de Tours, 2 boulevard Tonnellé, 37044 Tours cedex 9, France; Université François-Rabelais de Tours, PRES Centre-Val de Loire Université, 60 rue du Plat d'Etain, 37020 Tours cedex 1, France; CHRU de Tours, 2 boulevard Tonnellé, 37044 Tours cedex 9, France.

出版信息

J Clin Epidemiol. 2015 Aug;68(8):944-9. doi: 10.1016/j.jclinepi.2015.03.007. Epub 2015 Mar 21.

DOI:10.1016/j.jclinepi.2015.03.007

PMID:25892193

Abstract

OBJECTIVES

We aimed to assess whether the clinical equipoise principle is satisfied in unbalanced randomized controlled trials (RCTs) (i.e., with an unequal probability of subjects being allocated to one group than another).

STUDY DESIGN AND SETTING

Observational and comparative study between unbalanced and balanced RCTs. We searched the "core clinical journals" of MEDLINE to identify reports of two-parallel group superiority unbalanced RCTs published between January 2009 and December 2010. For each unbalanced RCT, we identified a maximum of four reports (to maximize power) of matched balanced RCTs dealing with the same population. Our primary outcome was the proportion of positive RCTs [i.e., with statistically significant results for the primary outcome (P < 0.05), showing greater efficacy with the new treatment than the control treatment].

RESULTS

We selected 46 reports of unbalanced RCTs and 164 of balanced RCTs; 65.2% unbalanced RCTs and 43.9% of balanced RCTs were positive (odds ratio, 2.38; 95% confidence interval: 1.23, 4.63). As compared with balanced RCTs, unbalanced RCTs were more often industry funded and their control treatments were more often inactive. Adjusting for these latter variables did not modify the results.

CONCLUSION

This result questions the respect of clinical equipoise in unbalanced RCTs.

摘要

目的

我们旨在评估临床均衡原则是否适用于不平衡随机对照试验（RCT）（即，受试者被分配到一组的概率与另一组不同）。

研究设计与设置

不平衡与平衡 RCT 之间的观察性和比较性研究。我们搜索了 MEDLINE 的“核心临床期刊”，以确定 2009 年 1 月至 2010 年 12 月期间发表的两平行组优势不平衡 RCT 的报告。对于每个不平衡 RCT，我们最多确定了四份报告（以最大限度地提高效力），这些报告涉及相同人群的匹配平衡 RCT。我们的主要结局是阳性 RCT 的比例[即，对于主要结局（P < 0.05）有统计学意义的 RCT，显示新治疗比对照治疗更有效]。

结果

我们选择了 46 篇不平衡 RCT 和 164 篇平衡 RCT 的报告；65.2%的不平衡 RCT 和 43.9%的平衡 RCT 为阳性（比值比，2.38；95%置信区间：1.23，4.63）。与平衡 RCT 相比，不平衡 RCT 更常由工业界资助，其对照治疗更常无效。调整这些后变量并没有改变结果。