The end-goal of any good doctor’s work should be the diagnosis of a patient to enable effective management and treatment but also to give the patient a possible prognosis. In a personal view in the BMJ last year, Gordon Caldwell, a consultant physician working in acute medicine, said that the time taken to reach the correct diagnosis may be crucial for the patient’s chance of survival. He added that over his career, he has seen many errors in the working diagnosis causing harm to patients and even death.