Methodology and rationale for the measurement of harm with trigger tools.

The growing recognition of harm as an unwelcome and frequently unrecognized byproduct of health care has initiated focused efforts to create highly reliable organizations for safe healthcare delivery. While debate continues over the exact magnitude of harm, there is a general acceptance of the need to improve our ability to deliver care in a safer manner. A major barrier to progress in safety has been the ability to effectively measure harm consistently and thus develop effective and targeted strategies to prevent its occurrence. This has resulted in a shift from initiatives focused exclusively on analysis of errors to those targeting events linked to harm. There is a growing recognition of a distinction between errors and adverse events as they often represent unique concepts fostering different strategies for improvement of safety. Conventional approaches to identifying and quantifying harm such as individual chart audits, incident reports, or voluntary administrative reporting have often been less successful in improving the detection of adverse events. As a result, a new method of measuring harm--the trigger tool--has been developed. It is easily customized and can be readily taught, enabling consistent and accurate measurement of harm. The history, application, and impact of the trigger tool concept in identifying and quantifying harm are discussed.