Glise H, Hallerbäck B, Oden A
Scand J Gastroenterol Suppl. 1987;127:55-9. doi: 10.3109/00365528709090952.
A drug trial concerned with peptic ulcer treatment has to be carefully planned to make possible a valid conclusion. Calculations of the number of patients required have to be made early. This depends upon factors such as: if the comparison is to be made between two active drugs or an active drug and a placebo, if the aim is to show that two treatments are almost equal or if a certain difference is expected, the number of groups to be compared, and if intermediate checks are to be made. Thus, from a few dozen patients up to several thousand may be needed. If a multicenter dosing is adopted, which is often necessary, the minimum number of patients required from each centre should be specified and a good reporting system has to be created. When presenting the results, it is preferable to calculate a confidence interval for the difference between the treatments--especially in small studies where the risk is false conclusions would otherwise be large.
一项关于消化性溃疡治疗的药物试验必须精心规划，以便得出有效的结论。必须尽早计算所需的患者数量。这取决于多种因素，例如：比较是在两种活性药物之间进行，还是在活性药物与安慰剂之间进行；目的是表明两种治疗方法几乎相同，还是预期有一定差异；要比较的组的数量；以及是否要进行中期检查。因此，可能需要几十名到几千名患者。如果采用多中心给药方式（这通常是必要的），应规定每个中心所需的最少患者数量，并建立良好的报告系统。在呈现结果时，最好计算治疗之间差异的置信区间——尤其是在小型研究中，否则得出错误结论的风险会很大。
