Early efforts to understand and analyze safety incidents in clinical medicine were drawn from a well-known James Reason book and his description of the "Swiss cheese model" for errors. Since that time, many researchers have tried to provide additional frameworks that help define the root causes and key failure modes. This systematic review analyzed nearly 100 articles to establish a contributory factors framework that could be applied to evaluating safety incidents in hospital settings. A set of 20 domains were ultimately outlined with most studies identifying individual factors, communication, and equipment and supplies as most frequently reported. The authors suggest that a consistently adopted framework would substantially improve our ability to not only identify contributing factors but also learn from them.