About six elderly sufferers of dementia get lost every day, according to a study by Chinese University's School of Public Health. It interviewed about 380 families with members over 65 believed or known to have dementia. About 23 per cent reported they had got lost at least once, but only a quarter called police. The problem is becoming more common as the population ages. Last year the police received 505 reports of dementia sufferers getting lost, more than double the 188 cases in 2002.