Participation and selection in three screening rounds
| Round 1 | Round 2 | Round 3 | Overall | |
| Invited | 13 269 | 25 189 | 38 395 | 76 853 |
| Filled in questionnaire (% of invited) | 2973 (22%) | 3825 (15%) | 4381 (11%) | 11 179 (15%) |
| Average score* (95% CI) | 6.16 (6.07 to 6.25) | 6.41 (6.33 to 6.48) | 6.31 (6.23 to 6.38) | 6.30 (6.26 to 6.35) |
| Sufficient score (% respondents) | 1851 (62%) | 2480 (65%) | 2777 (63%) | 7108 (64%) |
| Package returned (% package requests) | 1477 (80%) | 1927 (78%) | 2149 (77%) | 5553 (78%) |
| Positive test (% of tested) | 74 (5.0%) | 103 (5.3%) | 90 (4.2%) | 267 (4.8%) |
↵* Average score of all persons who filled in the questionnaire.