STUDY OF MULTI-CENTER CLINICAL TRIALS

多中心临床试验(MCCT)是临床研究的重要工具。 临床研究人员的医疗机构。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 在短时间内登记所需数量的样本患者。 尽管中心遵循相同的临床方案，但 临床中心可能是变异的一个重要来源。什么时候 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，这组中心是否表现出 作为固定效果还是随机效果？如果将这组中心视为 随机性强，设置的中心数小，对考核的影响 治疗结果可能会受到严重影响。这项研究的目的 是为了展示临床中心集合的变异性如何 能不能影响治疗效果的解读。 在第一个模型中，我们改变了中心的数量，但保持了平均值 以及处理效果常数的变化。如果五个中心是 无论是否使用，治疗效果在统计学上都是显著的 这组中心是被视为随机效应还是固定效应。 当中心的数量从5个减少到2个时，治疗是 在固定效应模型中具有统计学意义，但 在随机效应模型中不显著。在第二个模拟中， 我们改变了每个治疗组的反应之间的平均差异 医疗中心，治疗效果显著的固定 模特。在随机效应模型中，处理不显著， 在第三个模拟中，我们改变了处理组的方差 各医疗中心的响应情况。在固定效应模型中，处理 意义重大。在随机效应模型中，处理是 无关紧要。 模拟研究显示治疗效果有显著差异 取决于该组中心是否被视为具有固定和 随机效果。解释结果需要理解和理解 对指导数据分析的假设进行论证。

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.