Questionnaires
Participating survivors and siblings were asked to complete an updated questionnaire on general health and lifestyle. Survivors and siblings who participated in the LATER 1 questionnaire study in 2012—2014 (Teepen at al. submitted) received an abbreviated version of this questionnaire focusing on main health outcomes only (Supplemental information Table 3). Several other outcomes were assessed with, mostly validated, questionnaires (Supplemental information Table 4). Each survivor was invited to complete outcome-specific questionnaires for sub-studies for which the survivor was eligible. Questionnaires were spread in time (before, during and after the outpatient clinic recruitment visits) in order to limit the burden for survivors. Siblings of survivors also received questionnaires on psychosocial outcomes, fatigue, and skin health and parents of survivors received questionnaires on psychosocial outcomes.