抄録
In clinical trials involving repeated measures, missing data may occur for various reasons. Missing data not only cause loss of information of clinical trials, but are also a potential source of bias and loss of precision of the evaluation results, subsequently may lead to erroneous conclusions. Therefore, efforts to minimize the generation of missing data are necessary when planning to conduct a study. Furthermore, missing data imputation and statistical methods for handling missing data are being examined and discussed in academic societies. From the side of regulatory authorities, the European Medicines Agency (EMA) published the “Guidelines on Missing Data in Confirmatory Clinical Trials” in 2009, which describes the treatment and interpretation of missing data. This article shows our experience of imputation of missing data using modified total sharp score (mTSS), which is an index of joint damage progression, in a clinical trial on patients with rheumatoid arthritis. Some imputation methods and statistical methods are applied to dummy data that are based on the actual clinical trial, and the results are compared and discussed.
