Observational Cross-Sectional Study to Estimate Population Norms in Eight Countries: the POPUP Study Protocol

This study protocol outlines the Population Norms Study (POPUP), a multinational digital survey aimed at establishing general population norms for medical resource use, comorbidities, sick leave, caregiver support, quality of life, and functioning across eight countries: United States (US), Canada, United Kingdom (UK), the Netherlands, Belgium, Spain, Italy, and Germany. Data will be collected through an online self-administered survey in two waves: the first in Q1 2021 and the second in Q1 2023, when first-wave responders will be recontacted. A total of 15,500 responses will be gathered across both waves: 9,000 in the first wave and 4,500 re-contacts in the second, with an additional 2,000 new contacts if needed. Representative panels will be recruited by a research company from each country based on age, gender, education, and region. Participants will complete the survey after providing informed consent. No personal identifiers will be recorded. The observational study involves no medical interventions, drugs, or devices, and will be submitted for Ethical Committee approval in each country. Descriptive statistics will be used for data analysis. The results are expected to provide a baseline for comparing health outcomes in specific patient populations and quantifying disease burden.