Outcome measures
[Inactive disease, pain
The primary outcome measure was pain intensity. This was assessed using a 100 mm visual analogue scale (VAS), where 0 mm is ‘no pain’ and 100 mm is ‘unbearable pain’. Patients were asked to rate their pain over the last 7 days. Under the age of 12, pain was estimated by the parents. A VAS pain of ≤ 35mm is considered ‘mild pain’, whereas ‘moderate pain’ is defined as 36–60 mm and ≥ 61mm as ‘severe pain’ [Inactive disease was defined by the adjusted Wallace criteria [