Diagnostic error, Dual process model of reasoning) During the last decade, much emphasis has been placed on system solutions to patient safety problems. However, diagnostic error, despite being responsible for twice as many adverse events as medication error, has received little attention. The rate of diagnostic errors have been estimated to be between 0.6% to 12%.Some estimates are as high as 15%.The rate of negative outcome or adverse effects of diagnostic errors range from 6.9% to 17%. Most authors accept that the dual process model of reasoning explains how clinicians make diagnoses. The purpose of this study is to investigate why diagnostic errors occurred in the emergency departments (EDs).

Diagnostic error, Dual process model of reasoning) During the last decade, much emphasis has been placed on system solutions to patient safety problems. However, diagnostic error, despite being responsible for twice as many adverse events as medication error, has received little attention. The rate of diagnostic errors have been estimated to be between 0.6% to 12%.Some estimates are as high as 15%.The rate of negative outcome or adverse effects of diagnostic errors range from 6.9% to 17%. Most authors accept that the dual process model of reasoning explains how clinicians make diagnoses. The purpose of this study is to investigate why diagnostic errors occurred in the emergency departments (EDs). A qualitative study approach was used with in-depth semi-structured interviews conducted with emergency physicians to investigate the cognitive diagnosis process. The study takes place in the EDs of three hospitals in Taiwan. We chose the participants using a purposive sampling technique to yield a sample that would be most likely contribute significant information on the diagnostic process. Sampling continued until novel information was no longer being gathered. All audiotapes were transcribed verbatim. The transcripts are analyzed by two of the investigators based on the ground theory. Once all relevant codes were identified, they were grouped together into meaningful categories. These categories were then grouped under appropriate themes, which were used to generate a theory of diagnostic errors.

Inclusion Criteria:

• trained emergency physicians

Exclusion Criteria:

• refused interview

emergency physicians