In our school, the number of people absent due to illness started off very low in the first few weeks. This could be down to people being rested from the holidays or it could be that there is less illness at this time of year. It’s also likely that at the start of the school year students and parents have “fresh start” attitude. Parents are maybe more likely to encourage their children into school when ill to “keep up a good record” or to not miss too much school. Later in the year, this effect is probably a lot less important.