A 2 year study published in the October 18, 2006 issue of the Journal of the American Medical Association, (JAMA), found that during the study period, 21,298 adverse drug event cases were reported in the sampling group. Transposed nationally, the researchers estimate that 701,547 individuals suffered adverse drug reactions serious enough to require hospitalization.
The study was developed by the federal Centers for Disease Control and Prevention, the Food and Drug Administration and the United States Consumer Product Safety Commission. It looked at 63 hospitals in 2004 and 2005. The study found that people over 65 were most at risk and that a handful of drugs appear to produce a disproportionately high amount of adverse effects requiring emergency room visits and, in many cases, hospitalization.
Lead author Dr. Daniel Budnitz, a medical epidemiologist at the Centers for Disease Control and Prevention's National Center for Infectious Diseases, in an interview in an October 17, 2006 Newsweek article was asked if he was surprised at the high number. His response was, "Actually, it is most likely an underestimate. It might just pick up a third of the emergency visits—the number could be much higher. We don't know how much. But we are confident that there were at least 700,000 emergency department visits. Another point to remember is that these are medications that we're giving to patients to help them, and they are experiencing some degree of harm. So some might argue that even one of these events is bad. All drugs have benefits and risks, so it's probably unfair to say that every ER visit is unavoidable. But many of these events, especially the most severe—are due to this handful of drugs that we already knew we need to closely monitor."
In an October 18, 2006 New York Times article, professor Bruce Lambert, who was not involved in the research, and is a professor at the college of pharmacy at the University of Illinois, Chicago, commented, "This is an important study because it reinforces the really substantial risks that there are in everyday use of drugs."
Authors of the study concluded, "Adverse drug events among outpatients that lead to emergency department visits are an important cause of morbidity in the United States, particularly among individuals aged 65 years or older. Ongoing, population-based surveillance can help monitor these events and target prevention strategies."