A new University of Florida study casts doubt on one of hospitals' primary fall-prevention measures, bed alarms, which were designed to alert medical staff when patients are getting up when they're not supposed to. The study highlights a persistent problem for hospitals and the leading cause of injury and death for adults older than 65. U.S. emergency departments treat more than 2 million such injuries a year, according to the Centers for Disease Control and Prevention, at a cost of about $30 billion. An 18-month review of nearly 28,000 patients, using 349 beds, at Tennessee Methodist Healthcare University Hospital found that the alarms did not translate into fewer falls. This happened despite medical staff training in their use and hospital promotion of them, according to the study.