Professor Karina Butler:

No, it is actually very difficult. With the best will in the world it is extraordinarily difficult to capture figures on something like this when one is relying on GPs around the country reporting it. It seems simple and it would be good information. We can absolutely try to do it but it is extraordinarily difficult. Even when we have tried to find such figures on very defined diseases, for example, the number of children with chicken pox outside of those who end up in hospital, it is almost impossible to get those numbers.