Development of the pediatric quality of life inventory neurofibromatosis type 1 module items for children, adolescents and young adults: qualitative methods.

Health-related quality of life (HRQOL) is arguably one of the most important measures in evaluating effectiveness of clinical treatments. At present, there is no disease-specific outcome measure to assess the HRQOL of children, adolescents and young adults with Neurofibromatosis Type 1 (NF1). This study aimed to develop the items and support the content validity for the Pediatric Quality of Life Inventory™ (PedsQL™) NF1 Module for children, adolescents and young adults. The iterative process included multiphase qualitative methods including a literature review, survey of expert opinions, semi-structured interviews, cognitive interviews and pilot testing. Fifteen domains were derived from the qualitative methods, with content saturation achieved, resulting in 115 items. The domains include skin, pain, pain impact, pain management, cognitive functioning, speech, fine motor, balance, vision, perceived physical appearance, communication, worry, treatment, medicines and gastrointestinal symptoms. This study is limited because all participants are recruited from a single-site. Qualitative methods support the content validity for the PedsQL™ NF1 Module for children, adolescents and young adults. The PedsQL™ NF1 Module is now undergoing national multisite field testing for the psychometric validation of the instrument development.