Quality of life
Quality of life was assessed by PedsQlTM4.0 questionnaire applied according to the age group. This questionnaire has versions for five to seven years old (answered by their parents), eight to twelve years old and thirteen to eighteen years old. The domains are physical, emotional, social and school aspects. Each problem was asked for the adolescent or parents in the last month on a five-level response scale (0 = never a problem; 1 = almost never a problem; 2 = sometimes a problem; 3 = often a problem; 4 = almost always a problem). For children aged 5 to 7, the scale is simplified to three points (1 = not at all; 2 = sometimes; 3 a lot), with each answer anchored on a similar scale visual with happy, neutral and sad faces respectively. The items are score-reverse and linearly transformed to a scale from 0 to 100 (0 = 100, 1 = 75, 2 = 50, 3 = 25, 4 = 0). Therefore, high scores indicate better QOL. PedsQl TM4.0 scores are computed by adding the items divided by the number of items answered.16,17