The Study Protocol for GENESIS: GENEral population normS—An International Survey

Abstract Background Chronic autoimmune diseases such as Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), Multifocal Motor Neuropathy (MMN), and Thyroid Eye Disease (TED) impose a considerable burden on affected individuals. Patient-reported outcome measures (PROMs)—both disease-specific and generic—are widely used to assess functioning, quality of life, and treatment effects in these populations. However, most PROMs currently lack reference values derived from the general population, limiting the interpretability of patient scores. Objective The GENESIS (GENEral population normS—An International Survey) study aims to establish general population norms for a range of PROMs used in CIDP, MMN, and TED across six countries: Germany, Italy, Japan, Spain, the United Kingdom, and the United States. These norms will improve patient score interpretation and help quantify unmet needs in patients with these rare autoimmune diseases. Methods GENESIS is an observational, cross-sectional, online survey of the adult general population (N=21,000). Participants will be recruited to be representative by age, gender, region, and education. The survey includes validated instruments such as the EQ-5D-5L, I-RODS, MMN-RODS, CAP-PRI, GO-QoL, BPI-SF, RT-FSS, FACIT-Fatigue, HADS, and WPAI, along with items on demographics, caregiver need, and healthcare utilization. To reduce respondent burden, participants will be randomized into two groups, each completing a subset of the full questionnaire. A subset of respondents (n=2,333) will be re-surveyed after two months to support psychometric validation. Data will be analyzed descriptively to generate normative values for each PROM by country and in aggregate. Results and Dissemination Data collection is scheduled to begin in August 2025, with results expected by Q4 2025. Findings will be disseminated via peer-reviewed publications and conference presentations. Conclusion GENESIS will provide foundational normative data across six countries for PROMs commonly used in rare autoimmune diseases. These data will support more meaningful interpretation of PROM scores in both clinical practice and research settings.