Development of the QOL-PCD: A cross-cultural patient-reported outcome measure for adults with primary ciliary dyskinesia

Background: PCD is an autosomal recessive disorder characterised by chronic suppurative lung disease, rhinosinusitis, hearing impairment and sub-fertility. In EU-FP7 project “BESTCILIA”, we developed a health-related quality of life questionnaire for adults with PCD (QOL-PCD). Uniquely, we developed the questionnaire across continents (Europe & North America) to ensure that the measure was cross-culturally appropriate and harmonized. Methods: FDA and EMA guidelines were followed. Open-ended interviews about the impact of PCD were conducted with patients, followed by transcription and content-analysis (UK/Ireland n=12; USA n=12). In UK items were rated for relevance and importance by patients (n= 49) and PCD specialists from the European PCD Group n=40. Qualitative and quantitative data were used to develop a prototype questionnaire that was refined after cognitive testing (UK n= 9; US n= 6). Regular conference calls throughout the development and data review stages ensured a harmonized instrument. Results: Saturation grids generated from analysis of the qualitative data (Atlas.ti/ Nvivo) confirmed comprehensive coverage of content. The data were used to generate 8 items covering the following scales: physical functioning, emotional functioning, treatment burden, respiratory & sinus symptoms, ears & hearing, social functioning and vitality & health. Cognitive testing enabled us to refine wording, and to ensure QOL-PCD-adult was comprehensive. Conclusions: The adult version of PCD-QOL has demonstrated face validity and cross-cultural validity in cognitive interviews. PCD-QOL is now being translated into other languages prior to psychometric testing.