A patient safety incident investigation (PSII) is undertaken when an incident or near-miss indicates significant patient safety risks and potential for new learning. Investigations explore decisions or actions as they relate to the situation. The method is based on the premise that actions or decisions are consequences, not causes, and is guided by the principle that people are well intentioned and strive to do the best they can. The goal is to understand why an action and/or decision was deemed appropriate by those involved at the time.
This NHS England document provides an overview of patient safety incident investigation stages, tips and suggested structure for analysis.