Single-Center Trials Show Larger Treatment Effects Than Multicenter Trials: Evidence From a Meta-epidemiologic Study
Single-Center Trials Show Larger Treatment Effects Than Multicenter Trials: Evidence From a Meta-epidemiologic Study
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DOI：
10.7326/0003-4819-155-1-201107050-00006
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发表时间：
2011-07-05
影响因子：
39.2
通讯作者：
Ravaud, Philippe
中科院分区：
文献类型：
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作者：
Dechartres, Agnes;Boutron, Isabelle;Ravaud, Philippe
背景资料：最近的一项研究表明，当在多中心环境中进行类似的试验时，单中心试验的结果经常相互矛盾。目的：进行一项荟萃流行病学研究，以评估单中心和多中心随机对照试验（RCT）之间的治疗效果估计值是否存在差异。数据来源：通过PubMed检索MEDLINE，对2008年8月至2009年1月以及2010年前6个月发表在各医学期刊10种主要期刊上的具有二元结局的RCT进行分析。专业。检索了一期科克伦系统评价数据库;研究选择：选择纳入荟萃分析的所有单个RCT;数据提取：提取数据并使用科克伦协作网的偏倚风险工具评估其质量;数据综合：主要结局是比值比（ROR），用于量化单中心和多中心RCT之间估计干预效果的差异。ROR小于1表示单中心试验中干预效果的估计值较大。进行敏感性分析，调整样本量、RCT内偏倚风险和对数比值比方差，以考虑发表偏倚。共纳入48项荟萃分析，包括421项RCT（223项为单中心，198项为多中心）。单中心随机对照试验的干预效果大于多中心随机对照试验（合并ROR，0.73 [95% CI，0.64 - 0.83]），个体荟萃分析的异质性较低（I-2 = 12.0%; P = 0.24）。调整样本量得到一致的结果（ROR，0.85 [CI，0.74 - 0.97]），以及对RCT内偏倚风险的调整，如分配隐藏（ROR，0.76 [CI，0.67 - 0.86]）和对数比值比方差（ROR，0.83 [CI，0.72至0.96]）。局限性：尽管敏感性分析，荟萃混杂不能完全excluded.Conclusion：单中心随机对照试验显示更大的治疗效果比多中心随机对照试验，这一发现是一致的，在所有的敏感性分析。这些结果表明，在解释RCT和荟萃分析的结果时，应考虑该项目。
Background: A recent study suggested that results of single-center trials are frequently contradicted when similar trials are performed in multicenter settings.Purpose: To perform a meta-epidemiologic study to evaluate whether estimates of treatment effect differ between single-center and multicenter randomized, controlled trials (RCTs).Data Sources: MEDLINE was searched via PubMed for meta-analyses of RCTs with binary outcomes that were published between August 2008 and January 2009 and in the first 6 months of 2010 in the 10 leading journals of each medical specialty. One issue of the Cochrane Database of Systematic Reviews was also searched.Study Selection: All individual RCTs included in the meta-analyses were selected.Data Extraction: Data were extracted and their quality was assessed by use of the risk of bias tool of the Cochrane Collaboration.Data Synthesis: The primary outcome was the ratio of odds ratios (ROR), used to quantify the difference in estimated intervention effect between single-center and multicenter RCTs. An ROR less than 1 would indicate larger estimates of the intervention effect in single-center trials. Sensitivity analyses were performed with adjustment for sample size, risk of bias within RCTs, and variance of the log odds ratio to take publication bias into account. Forty-eight meta-analyses were selected, including 421 RCTs (223 were single-center and 198 were multicenter). Single-center RCTs showed a larger intervention effect than did multicenter RCTs (combined ROR, 0.73 [95% CI, 0.64 to 0.83]), with low heterogeneity across individual meta-analyses (I-2 = 12.0%; P = 0.24). Adjustment for sample size yielded consistent results (ROR, 0.85 [CI, 0.74 to 0.97]), as did adjustment for risk of bias within RCTs, such as allocation concealment (ROR, 0.76 [CI, 0.67 to 0.86]), and variance of log odds ratio (ROR, 0.83 [CI, 0.72 to 0.96]).Limitation: Despite sensitivity analyses, meta-confounding cannot be fully excluded.Conclusion: Single-center RCTs showed larger treatment effects than did multicenter RCTs, a finding that was consistent in all sensitivity analyses. These results suggest that this item should be considered when the results of RCTs and meta-analyses are interpreted.