Table 1.

Sampling design: clustering of the Primary Sampling Units (PSU), selection of the PSUs, and sampling within the PSU

Age groups

Target: 3 age groups: •children aged 6-11 years •teenagers aged 12- 19 years •young adults aged 20-39 years

Primary sampling unit (PSU)

Country based, 27* EU HBM4EU participating countries

EU wide coverage (clustering of PSUs)

PSU are clustered per EU geographical region**: •Northern Europe (DK, FI, SE, IS, NO, LV, LT, IE, UK, EE) •Western Europe (AT, BE, NL, FR, DE, CH, LU) •Southern Europe (HR, CY, EL, IT, PT, Sl, ES, MK) •Eastern Europe (CZ, PL, SK, HU)

EU wide coverage (selection of PSU)

Inclusion of number of PSU (countries) per region proportional to number of inhabitants of the region. •2 PSU for Northern Europe: 21% •3-4 PSU for Western Europe: 40% •3 PSU for Southern Europe: 28% •At least 1 PSU for Eastern Europe: 11%

National representativeness

•PSU representative on national level preferred, PSU representative on regional level also accepted.

Sampling design within the PSU

•Min 240 - max 300 subjects with a 1:1 male female ratio

*Current HBM4EU consortium consists of 30 countries including Israel (non-EU) and Estonia and Republic of North Macedonia who joined the HBM4EU consortium in a later stage, ** following the United Nations geoscheme subregion of Europe. DK = Denmark, FI = Finland, SE = Sweden, IS = Iceland, NO = Norway, LV = Latvia, LT = Lithuania, IE = Ireland, UK = United Kingdom, EE = Estonia, AT = Austria, BE = Belgium, NL = The Netherlands, FR = France, DE = Germany, CH = Switzerland, LU = Luxembourg, HR = Croatia, CY = Cyprus, EL = Greece, IT = Italy, PT = Portugal, Sl = Slovenia, ES = Spain, MK = North Macedonia, CZ = Czech Republic, PL = Poland, SK = Slovakia, HU = Hungary.