OBJECTIVES: Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare, genetic disorder in which heterotopic ossification causes severe, irreversible disability. We present results from an international burden of illness survey (NCT04665323) assessing the humanistic and economic impact of FOP on primary caregivers.

METHODS: Primary caregivers of individuals with FOP across 15 countries completed the online survey from 18Jan21–30April21. A bespoke, FOP-specific questionnaire assessed the social/emotional impact of FOP on family members. The Zarit Burden Interview (ZBI) evaluated the impact of caring for a family member with FOP on the primary caregiver’s health/psychological wellbeing (total score: 0[little/absent]–88[severe]). The impact of FOP on the primary caregiver’s career was also assessed.

RESULTS: 163 primary caregivers responded to the survey; mean (standard deviation [SD]) age was 49.2 (12.0) years and 85.4% identified as female. Primary caregivers reported a large emotional impact of FOP; most described finding out their family member had FOP as very/extremely difficult (86.6%) and flare-ups as very/extremely stressful (89.7%). The most common activities that primary caregivers reported as ‘always’ assisting their family member with FOP were preparing meals (65.4%), bathing (65.2%) and getting dressed (58.8%); mean (SD) hours per day spent looking after their family member was 10.6 (8.6). 45.1% of primary caregivers had a ZBI score indicating a mild to moderate impact on their health/psychological wellbeing. Most primary caregivers supporting the youngest patients (<8 years) reported a mild to moderate impact (56.7%); 57.7% of those caring for older patients (≥25 years) reported little or no impact. 51.3% of primary caregivers felt they needed to adapt their career to support their family member with FOP.

CONCLUSIONS: Primary caregivers reported experiencing wide-ranging humanistic and economic impacts. These data help to better understand the personal and societal impact of caring for an individual with FOP and may inform additional support strategies for the FOP community.