Which type of medical error involves planning errors, wrong decisions, or knowledge gaps?

• A. Slips/Lapses
• B. Mistakes
• C. Violations
• D. Omissions

Answer: (B)

Mistakes are errors that come from planning or decision-making problems, often tied to gaps in knowledge or faulty reasoning. When a clinician makes a wrong judgment or selects an inappropriate plan because of incomplete understanding or an incorrect mental model, that’s a mistake. It differs from slips or lapses, which are execution problems where the right plan is known but an action is carried out incorrectly or forgotten due to attention or memory failures. It also differs from violations, which are deliberate deviations from rules or procedures, and from omissions, which are failures to take an action that should have been done. For example, choosing an inappropriate treatment plan due to not fully understanding a drug’s interactions is a mistake.