In the work process of nurses with high risk, it is very urgent to take countermeasures against the “lack of confirmation” of the main factors. Therefore, the purpose of this study is to clarify the details of the factors leading to the lack of confirmation, grasp the number of near misses, and to explore what kind of factors the individual characteristics of the nurse who acts as a stopper. We recruited 500 nurses on the Web and asked about the frequency of near misses due to lack of confirmation, the awareness of the causes of lack of confirmation, self-evaluation of stoppers, and the reasons why near misses did not lead to accidents. As a result, three factors were extracted regarding the recognition of the factors of lack of confirmation: "lack of consciousness", "inability to concentrate", and "lack of knowledge / experience". Three factors were extracted for self-evaluation of stopper characteristics: "awareness," "verification," and "cautiousness". In order to reduce the lack of confirmation, it is necessary to secure and allocate appropriate personnel and create an environment where treatment can be concentrated. Nurses should also raise knowledge and the awareness of the importance of confirmation. In addition, it is necessary to improve the clinical judgment of new nurses in order to prevent near misses. And it is thought that new nurses will
become more confident by accumulating experience and affirming their abilities from their superiors, seniors and colleagues.