What we don’t know can result in harm. Adverse events can happen from insufficient understanding. High inherent radiation risks, unnecessary CT scans, and inaccurately working CT scan machines used in 2007 were expected to cause 29,000 new diagnoses of cancers from overexposure to radiation, and may kill nearly 15,000 Americans, according to the Archives of Internal Medicine [1]. Even a treatment gets changed a third of the time if you seek a second opinion [2]. There are at least five classes of insufficient understanding as follows:

A. Insufficient understanding of system vulnerability. A prevalent form of insufficient understanding is to accept the notion that human errors cause accidents. This is never true! Accidents can only happen when hazards already exist in a system (example: an infected wheelchair or poor enforcement of sanitization policy), and a trigger event (an active error) is initiated such as a human error (using the infected

wheelchair to transport a patient or a technician keeps using a certain MRI, knowing that it is inaccurate).