Table 1.

IMPACT Survey design overview

	Population
Domain	Non-caregiver adults with OI	Caregiver adults with OIa, b	Caregivers without OIa	Adolescents with OI	Relatives
Participation criteria	≥ 18 years of age	≥ 18 years of age OI Self-describes as someone who provides care for individuals with OI	≥ 18 years of age Self-describes as someone who provides care for individuals with OI	≥ 12–17 years of age OI	≥ 12 years of age Self-assesses relationship to person with OI as close but does not self-describe as a caregiver
N questionsc	37–84	50–111	49–94	28–69	10–12
Clinical characteristics	Demographic data; for each person with OI: height, OI type, OI severity, causative gene, mobility status				Demographics
Clinical signs, symptoms and events	Signs, symptoms and events in past 12 months and lifetime				NA
Treatment and care experience	Diagnostic pathway, experience with healthcare providers, access to care				NA
QoL	Impact of OI on individuals(s) with OI, impact of signs, symptoms and events, worries				NA
Impact on families	NA	Impact on caregivers and impact on family life		NA	Impact of OI, worries
Healthcare consumption	Use of therapies in past 12 months and lifetime, use of inpatient and outpatient care, consumable use				NA
Financial sources for treatment	Insurance coverage, out of pocket spending			NA	NA

NA, not applicable; OI, osteogenesis imperfecta; QoL, quality of life

^aCaregivers provided information on 1–3 care recipients with OI of any age; ^bCaregivers with OI only provided information about their OI and their experience of caring for individuals with OI, they did not report about the OI experience of individuals in their care; ^cThe minimum includes compulsory questions without any follow-up questions that only applied to subgroups, the maximum includes all compulsory and optional questions