STUDY OF MULTI-CENTER CLINICAL TRIALS

多中心临床试验（MCCT）是临床试验的重要工具。 临床研究人员的医疗设备 多个站点使用公共 评估治疗安全性和有效性的治疗方案 MCCT。 如果感兴趣的疾病相对罕见，MCCT可以 在短时间内招募所需数量的样本患者。 即使中心遵循相同的临床方案， 临床中心可能是变异性的重要来源。 当 在分析数据时，必须对以下行为做出假设： 临床中心设置。 具体地说， 是固定效应还是随机效应 如果中心的集合被视为 随机性和中心设置数量少，对评估的影响 治疗效果可能会受到严重影响。 本研究的目的 是为了证明一组临床中心的变异性 会影响对治疗效果的解释。 在第一个模型中，我们改变了中心的数量，但保持了平均值 和处理效应常数的方差。 如果五个中心 使用时，治疗效果具有统计学显著性，无论 将中心集视为随机效应还是固定效应。 当中心数量从五个减少到两个时， 在固定效应模型中具有统计学显著性，但 在随机效应模型中不显著。 在第二次模拟中， 我们改变了治疗组反应之间的平均差异， 医疗中心，治疗在固定效应中具有显著性 模型 在随机效应模型中，治疗不显著， 在第三次模拟中，我们改变了处理组的方差， 每个医疗中心的反应。 在固定效应模型中， 有显著性 在随机效应模型中， 不显著。 模拟研究揭示了治疗效果的显著差异 取决于中心集是否被视为具有固定和 随机效应 解释结果需要理解和 指导数据分析的假设的理由。

The Multi-Center Clinical Trial (MCCT) is an important tool in the clinical researcher's armamentarium. Multiple sites using a common treatment protocol to assess treatment safety and efficacy characterize the MCCT. If the disease of interest is relatively rare, an MCCT can enroll the desired number of sample patients in a short period of time. Even though centers follow the same clinical protocol, the set of clinical centers may be a significant source of variability. When analyzing the data, assumptions must be made regarding the behavior of the clinical centers set. Specifically, does the set of centers behave as a Fixed or Random effect? If the set of centers is regarded as random and the set number of centers is small, the effect on assessing treatment results may be seriously affected. The purpose of this study was to demonstrate how the variability of the set of clinical centers can affect the interpretation of the effect of treatment. In the first model, we varied the number of centers but held the mean and variance of the treatment effect constant. If five centers were used, treatment effect was statistically significant regardless of whether the set of centers was treated as a random or fixed effect. When the number of centers was decreased from five to two, treatment was statistically significant in the fixed effects model, but non-significant in the random effects model. In the second simulation, we varied the mean difference between treatment group response in each medical center, and treatment was significant in the fixed effects model. The treatment was non-significant in the random effects model, In the third simulation, we varied the variance of treatment group response in each medical center. In the fixed effects models, treatment was significant. In the random effects model, treatment was non-significant. Simulation studies revealed significant differences in treatment effect depending on whether the set of centers was treated as having fixed and random effects. Interpreting the results requires an understanding and justification of the assumptions guiding the data analyses.