Qualitative Research in Children and Parents of Children with Achondroplasia to Evaluate the Content Validity of Multiple Clinical Outcome Assessments

Background. Achondroplasia is one of the most common skeletal dysplasias, characterized by disproportionate short stature and delayed motor development. Additional potential complications include bowed legs and hypotonia, otitis media, sleep apnea, and complications from spinal stenosis, which may impose potential burden to individuals with achondroplasia, as well as to their parents and family. No reliable, validated and publicly available achondroplasia-specific patient-reported outcome (PRO) measure is currently available that can capture the experiences of children and adolescents with achondroplasia. We sought to determine whether existing PRO measures have adequate concept coverage for use in clinical studies and understand the challenges for children/adolescents with achondroplasia and their parents through concept elicitation and cognitive debriefing interviews. Methods. Children/adolescents with achondroplasia and parents of children with achondroplasia participated in combined concept elicitation and cognitive debriefing interviews. Issues raised by participants were mapped to multiple PRO measures to evaluate their clarity, relevance, and appropriateness for use in achondroplasia studies. Results. Eight children/adolescents (aged 11 to 16) and 18 parents were interviewed. The challenges most often reported by children/adolescents were feeling hot/sweaty (88%), pain (88%), balance issues or falls (75%), fatigue (63%), muscle fatigue/loose joints (63%), and speech issues (63%). Pain (83%), ear infections (78%), and feeling hot/sweaty (78%) were frequently reported by parents. Difficulty reaching things (88%), running (88%), and walking (75%) were the functional challenges most reported by children/adolescents, while parents most commonly reported difficulty reaching things (78%), toileting (63%), bathing (56%), walking (56%), running (56%), and dressing (50%). Results of response mapping indicated that the QoLISSY, PedsQL, WeeFIM, and Pain-NRS cover most of the important concepts mentioned by parents and children/adolescents. Conclusions. The PedsQL, QoLISSY, Pain-NRS, and WeeFIM are content valid, appropriate, and relevant to include in future studies of individuals with achondroplasia.