OBJECTIVES: Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare genetic disorder of progressive heterotopic ossification, leading to severe disability. Despite advances in understanding the natural history of FOP, a comprehensive description of its impact on quality of life (QoL) and activities of daily living (ADL) for patients and their families is lacking. Here, we describe the first international, cross-sectional FOP burden of illness online survey (NCT04665323), developed with FOP community advisors, used to assess the impact of FOP on patients’ and their families’ QoL.

METHODS: Participants were recruited through the International FOP Association and national/regional FOP organizations. Individuals with FOP, their primary caregivers, and other family members (≥18 years) were eligible to participate. The survey was available online between 18Jan21–30Apr21 in 15 countries and 11 languages.

RESULTS: Over 400 individuals with FOP or family members responded. Participant demographics and patient medical history were collected. The EuroQoL health-related QoL questionnaire (EQ-5D-5L) and Patient-Reported Outcomes Measurement Information System (PROMIS) assessed the QoL impact of FOP on patients and their families. The professional, health, and social impact on primary caregivers was assessed through the Zarit Burden Interview (ZBI). The Patient-Reported Mobility Assessment (PRMA) and FOP Physical Function Questionnaire (FOP-PFQ) evaluated impact on patients’ ADL and physical functioning. Additional questions were specifically designed to assess the emotional and social impact on family members. Descriptive analyses will be performed overall and by age group, PRMA level, and body regions affected, as appropriate. Regression modeling will evaluate the relationship between increasing joint impairment (assessed by PRMA and/or body regions affected) and QoL measures.

CONCLUSIONS: These novel data will improve understanding of the impact of FOP on patients’ and their families’ QoL, which is important for identifying unmet needs, evaluating new healthcare interventions, and ultimately optimizing patient care.