In recent years, there has been increasing attention to assistive products and a growing demand for their scientific evidence for their use. Clinical trials are an important process to obtain evidence, and appropriate selection of outcomes is required to determine the results. However, unlike pharmaceuticals, there are no regulations on the provision system regarding efficacy, and therefore, there are too many degrees of freedom in evaluation, and the related information is not well organized. Therefore, we reviewed relevant domestic and international documents and extracted information that would be useful for selecting outcomes in clinical trials. As a result of our survey, we found that the pharmaceutical and medical device fields are ahead of the assistive product field in terms of clinical trials, and have organized information such as guidelines. In the area of assistive products, efforts to measure the effectiveness of products were progressed in Europe and the United States, and ideas on outcome classification and selection methods were presented. Although this study is not comprehensive, the findings are expected to be useful in planning future clinical trials in the field of assistive products.