Table 1 Sampling frame and procedures in each country participating in the MentDis_ICF65+ study

Sample frame

Registries of resident registration offices in the metropolitan area of Hamburg through a market research company

Registries of resident registration offices in Ferrara and the province

Post office address files in Greenwich Borough and Canterbury District through a market research company

Addresses of residents in Madrid from the Statistical Institute of Madrid, a private company, and the Madrid City Council

Addresses of residents in the Geneva canton through a marketing company

Addresses of Jewish residents in the greater Jerusalem area through a market research company

Stage 1

Stratification by age and gender

Stratification by age and gender

Stratification by age and gender

Stratification by age and gender

Stratification by age, gender, socio-economic status, city/rural location

Stratification by age and gender

Stage 2

random selection from a registry of 5640 participants

random selection from registry

- 1^st selection: 2000 participants

- 2^nd selection: 1918 participants

- 3^rd selection: 720 participants

random selection from files

- 1^st selection: 2977 participants

- 2^nd selection: 1145 participants

random selection from a census of 1072 participants (Madrid administration) and 1063 from files (private company)

random selection from registry

- 1^st selection: 2000 participants

- 2^nd selection: 700 participants

random selection

- 1^st selection: 2500 participants

- 2^nd selection: 708 participants