Although previous studies have found a decline in health-care use during major sporting events, the Children's Hospital Boston researchers are the first to quantify the magnitude of the events--using television Nielsen ratings--showing that the bigger or more suspenseful the event, the quieter the emergency department. Borrowing data from a real-time disease surveillance system developed at Children's, the researchers tracked hourly visit rates at six Boston-area emergency departments during each of the 2004 American League Champion-ship Series and World Series games. They plotted these rates against television viewership as indicated by local Nielsen ratings.