Some parents arent sure when to keep sick children away from school and when its OK to send them back. While many schools in Hong Kong make it easy for parents to decide, with clear-cut rules on illness, a US-wide poll by the University of Michigan C.S. Mott Childrens Hospital found parents differ on how sick is too sick for class, or the importance of sick day consequences such as missing work or children missing tests. The findings were based on responses from 1,442 parents who had at least one child between the ages of six and 18. Those with children aged between six and nine most frequently considered health issues as a key concern when opting for a sick day, while two in five parents of high schoolers rated missing tests or falling behind in class work equally. Five things you need to know about flu season in Hong Kong this year Symptoms also make a difference. According to the poll, 80 per cent of parents would keep home a child with diarrhoea, just 58 per cent a child with vomiting, and 49 per cent a child with a slight fever but still acting normally. Most parents say they are likely to send a child with red, watery eyes but no fever (16 per cent) to school, or one with a runny nose, dry cough and no fever (12 per cent).