Community clinical data exchange for emergency medicine patients

Little is known about the opportunities for a community clinical data exchange network to influence patient care. Rates of patient "cross-over" among different institutions can provide one estimate of the additional value such systems have over unconnected, independent institutional electronic medical records. The Indiana Network for Patient Care (INPC) represents such a system, involving a collaboration of central Indiana hospitals to improve patient care. During a one year study period, 288,696 patients made 471,640 Emergency Department (ED) visits within the INPC collaboration -- accounting for 92% of all Indianapolis ED visits. Overall 25% of the patients with more than one visit also visited one of the other five hospital systems, accounting for 19% of all visits. Our results help clarify the expected frequency within one large metropolitan area that ED patients could obtain direct benefit from a community clinical data exchange network.