An ICF-CY-based approach to assessing self- and observer-reported functioning in young persons with achondroplasia - development of the pilot version of the Achondroplasia Personal Life Experience Scale (APLES)

Purpose: Achondroplasia is the most common disproportionate short stature which impacts patients' well-being. Little is known about the burden of disease in terms of functioning of patients and few disease-specific patient-reported outcome (PRO) measures exist. To understand the consequences of achondroplasia, the objective of the study was to develop an achondroplasia-specific PRO tool. Method: Focus group discussions including 34 German patients (age 8-18 years) and 21 parents were conducted and qualitatively analyzed. To identify relevant concepts, statements were coded according to the International Classification of Functioning, Disability and Health: Children & Youth version (ICF-CY). Upon condensation, relevant statements were reformulated as items. Results: 1950 statements related to 125 ICF-CY categories were identified. After condensation and prioritization, 59 items were retained. These were generated based on the ICF-CY domains environmental factors (27 items), activities and participation (18 items), body functions (9 items), and body structures (5 items). Conclusions: A new instrument, the Achondroplasia Personal Life Experience Scale (APLES) to assess burden of disease and functioning from the patients perspective of children and adolescents with achondroplasia has been developed in its pilot version based on the classification of the ICF-CY. Psychometric performance of the APLES is currently being examined.