[1] Erasmus MC Sophia Childrens Hosp, Dept Paediat Oncol Haematol, Rotterdam, Netherlands
[2] Princess Maxima Ctr Paediat Oncol, Utrecht, Netherlands
[3] Vrije Univ Amsterdam, Dept Clin Psychol, Amsterdam, Netherlands
[4] Univ Southampton, Fac Hlth Sci, Southampton SO17 1BJ, Hants, England