Accidental poisoning deaths spike upward. Prescription drug overdoses, falls spur 11 percent surge in injury rate. Livescience. msnbc. Setember 02, 2009. For reasons not totally understood, the mortality rate from unintended injury in the United States rose 11 percent between 1999 and 2005, a new study finds. The jumps in poisoning deaths and deaths from falls were particularly high and troubling, researchers said.Overall, 89 percent of the total increase in unintentional injury deaths in the U.S. between 1999 and 2005 was due to poisoning among those 15 to 64 years old and falls among those 45 and older, which increased by about 11,200 and 6,600, respectively. [ See ]