Use of the top two most expensive codes for emergency room care nationwide nearly doubled, from 25 percent to 45 percent of all claims, during the time period examined. In many cases, these claims were not for treating patients with life-threatening injuries. Instead, the claims the Center analyzed included only patients who were sent home from the emergency room without being admitted to the hospital. Often, they were treated for seemingly minor injuries and complaints. While taxpayers footed most of the bill, the charges also hit elderly patients in the pocketbook, increasing the amount of their 20-percent co-payments for emergency room care.