RESUMO
Techniques such as 4M-4E matrices and the SHEL model have been proposed in recent years as tools for analyzing medical accidents and developing countermeasures. There have been hardly any reports, however, describing their use for the development of risk strategies in the medical setting. After using the SHEL model, Toranomon Hospital is currently using "Why Why Why Analysis" and has had several successes as a result of its use. With this in mind, a comparative study was conducted between "Why Why Why Analysis" and several previously reported accident countermeasure tools, root cause analysis (RCA), used at Veterans Hospitals in the US, and quality control (QC), used in the industrial sector. As a result, "Why Why Why Analysis" as applied in radiology work was determined to be easy to deploy even for beginners as compared with the other tools, able to accommodate complaints as well as accidents, and useful on the basis of having both practical and expandable functions for improving radiology work.