Accuracy of 'My Gut Feeling:' Comparing System 1 to System 2 Decision-Making for Acuity Prediction, Disposition and Diagnosis in an Academic Emergency Department.

Introduction: Current cognitive sciences describe decision-making using the dual-process theory, where a System 1 is intuitive and a System 2 decision is hypothetico-deductive. We aim to compare the performance of these systems in determining patient acuity, disposition and diagnosis.

Methods: Prospective observational study of emergency physicians assessing patients in the emergency department of an academic center.

Ultrasound evaluation of an inguinal mass.

A 33 year-old female presented to the emergency department (ED) with of two weeks of diffuse abdominal pain, right flank pain, and a slowly enlarging right inguinal mass. She had no associated fever, chills, nausea, vomiting, or diarrhea. She was evaluated by her primary care physician, and an inguinal ultrasound was obtained prior to referral to the ED.