The evidence that checklists can improve diagnostic safety is thin, which is surprising because the face validity of checklist use is high and several experts have promoted checklist use to reduce diagnostic errors. Furthermore, checklists have been very successful for addressing other threats to patient safety.1,2 Why is this not the case in diagnostic safety?
Successful checklists for preventing other error types list very specific tasks. For example, the first step in the well-known checklist to reduce central-line infections is “Wash your hands with soap,”1 and the widely adopted surgical checklist starts with confirming the patient’s identity.2 These checklists are meant to prevent errors of execution, so-called “slips” (attention failures) or “lapses” (memory failures).20 Typical for these errors is that the clinician had the right plan for the task but erred only in the execution (e.g., forgetting a step in the preoperative process, marking the wrong limb). These types of errors are easily prevented by a checklist that prevents clinicians from skipping steps in the process.
Conversely, checklists used for diagnostic safety seem to focus on errors of planning. These errors occur when the plan of an action was incorrect (e.g., due to lack of knowledge). A frequently used item on checklists in the diagnostic process is “What else can it be?”,13 which prompts the clinician to reconsider the diagnostic process and reflect on possible alternatives. In other words, clinicians are asked to evaluate the task they have just performed without any suggestion of what they might have missed. An important and unanswered question for diagnostic safety is whether checklists can prevent such errors. Even the current content-specific checklists for diagnostic safety may not be specific enough.