Johannessen T, Fosstvedt D, Petersen H
Department of Community Medicine and General Practice, University of Trondheim, Norway.
Scand J Gastroenterol Suppl. 1988;147:33-7. doi: 10.3109/00365528809099156.
A multi cross over model (MCOM) has been designed for single case studies. The model which is only partly randomized, implies regular interchanges between treatment periods with active drug and placebo. The individual evaluation is based on the number of times the active drug is associated with less symptoms than the preceding or following placebo period (X-score), while the effect in a group is evaluated according to the X-score distribution and a paired t-test. The advantages of the single case approach and the impact of the MCOM is illustrated by the results from a study of the effect of cimetidine in non ulcer dyspepsia. Although there are several statistical objections to the model, the results from the study are reasonable and demonstrate a small degree of violence of preassumptions.
一种多交叉模型（MCOM）已被设计用于单病例研究。该模型仅部分随机化，意味着在使用活性药物和安慰剂的治疗期之间有规律地交替。个体评估基于活性药物与前一个或后一个安慰剂期相比症状较少的次数（X评分），而组内效应则根据X评分分布和配对t检验进行评估。西咪替丁治疗非溃疡性消化不良的研究结果说明了单病例方法的优点以及MCOM的影响。尽管对该模型存在一些统计学上的异议，但研究结果是合理的，并表明预设假设存在一定程度的偏差。
