 Background diagnosis is a crucial component of effective healthcare, but misdiagnosis is common and can put patients at risk. Diagnostic decision support systems can play a role in improving diagnosis by physicians and other healthcare workers. Symptom checkers, SCs, have been designed to improve diagnosis and triage by patients. Objective the aim of this study was to evaluate the performance of the This article was authored by Hamish Fraser, Daven Crossland, Ian Backer, and others.