PLAN OF STUDY The investigators will send a letter of invitation to participate in the study and a research information sheet outlining the nature and importance of the study to eligible patients and their parents. The invitation letter will explicitly state that if they do not wish to take part in the study, it will not prejudice the quality of health care provision from the hospital. Two weeks later, the investigators will telephone all those who have not already responded, offering an invitation to participate and to answer any queries. Those who can not be contacted by telephone will be sent a second letter. Those who agree to take part will be interviewed by an investigator who will provide full information about the trial and obtain written informed consent. Prior to randomization, the following baseline demographic and clinical features will be recorded: patient's initials, date of birth, gender, hospital number, and disease activity (aPCDAI or PUCAI score). Participants will be provided with the contact details of relevant investigators.