People who return to the ED have multiple forces and motivations in play, including but not limited to:
Of course, from a practical standpoint, patients who are evidently sicker and return to the same or different emergency department usually get admitted to the hospital. Repeat discharge happens, ut it does so with peril, as there are frequently solid medical, medical-legal, and logistic reasons, to keep the patient the second time. Because beware willing to send home potential high risk bounce-back patients overall costs are inevitably driven up.
True interoperability, particularly by the establishment of industry-standard and required electronic documents, would greatly enhance patient safety by giving the next provider a better feel for what might have occurred at prior visits.