A significant portion of people -- perhaps as many as one in five -- don't take drugs a doctor has prescribed because they can't pay for them, according to a new survey of people visiting an emergency room. "I think this is a wake-up call," study author Karin Rhodes, MD, of the University of Pennsylvania told Reuters Health. Among a group of more than 1500 people who volunteered to complete a questionnaire, more than 20% said they had previously not taken a prescribed drug on account of the price tag. It's an issue that many doctors aren't aware of, noted Rhodes, and the system needs to address it. "Patients need to be asked 'can you afford your medications?' and they should get help to pay for them." A number of studies have shown that people with chronic health problems, including high blood pressure, diabetes and heart disease, commonly fail to take their medications as prescribed.