Training residents in medical incident report writing to improve incident investigation quality and efficiency enables accurate fact gathering.

We assessed whether training on writing readable and accurate medical incident reports (IRs) improves the quality of fact description. In this training, 124 residents created fictional IRs. We provided tips, including using When, Where, Who, What, Why, How. We compared the fictional IRs with and without tips, and the trainees' and non-trainees' IRs submitted in the first five months after training. Results indicated that the subject words in IRs were more clarified and the readability was improved. The fictional IRs using tips were more accurate, with increased descriptions of the patient's background, reporter's actions, team members' actions and conversations, safety check procedures, result of the error, and post-incident response. The reporter's actions, work procedures, and environment were more clarified in the trainees' IRs than in the non-trainees' IRs. This training may help analysts comprehend the sequence of and underlying factors for reporter's actions based on IRs.