 The study aims to test whether it is possible to reduce pressure on Emergency Departments by sending a personal feedback letter to people who have recently attended an Emergency Department and whose health issues could likely have been dealt with elsewhere. These attendances clearly have many causes. However, it is likely that some attendances are due to behavioural factors - in other words, the various ways in which users interact with services. This study focuses on one particular behavioural factor: lack of feedback to users making avoidable visits. 