Five out of six Americans who work outside the home are forced to quit their jobs, retire prematurely, cut back their work hours or take sick leave, vacation leave, or a leave of absence to take care of elderly relatives. That's the finding of a study conducted by the National Center on Women & Aging at Brandeis University. The study estimates that 22.4 million U.S. families -- nearly a quarter of all households -- provide care to elderly relatives, and that informal, home-based care accounts for 80% of all long-term care in the U.S. In addition, 29% of elder caregivers said they passed up promotions, training opportunities, and new assignments because of their elder care responsibilities. Another 22% said caregiving prevented them from acquiring new skills. Equally as troubling: almost 75% of those surveyed said caring for elderly relatives had harmed their health.