Table 1.
Invitees | Participated | n and % of participants accepting linkage of data to other health surveys and registers |
n and % of participants accepting DNA (Cyto-brush) |
||||
---|---|---|---|---|---|---|---|
Study | N | n | % | n | % | n | % |
Cross-sectional data collections | |||||||
15/16 years old, 2001 | |||||||
Oslo, school based (sample 1)1 | 4273 | 3811 | 89.2 | 3433 | 90.1 | ||
Hedmark, school-based (sample 2)1 | 2197 | 1939 | 88.3 | 1791 | 92.4 | ||
TOTAL, Oslo and Hedmark | 6470 | 5750 | 88.9 | 5224 | 90.9 | ||
18/19 year old, 2004 | |||||||
Oslo, school-based (sample 3)1 | 3659 | 3308 | 90.4 | 3036 | 91.8 | 3095 | 93.6 |
Three years follow-up of samples from 2001 | |||||||
18/19 years old, 2004 | |||||||
Oslo total (sample 4)1 | 3550 | 2735 | 77.0 | 2489 | 91.0 | 2527 | 92.4 |
School-based | 24662 | 2269 | 92.0 | 2105 | 92.8 | 2145 | 94.5 |
Postal-based | 10843 | 466 | 43.0 | 384 | 82.4 | 382 | 82.0 |
Hedmark, postal-based (sample 5)1 | 16834 | 933 | 55.4 | 827 | 88.6 | 828 | 88.7 |
TOTAL, Oslo and Hedmark | 5233 | 3668 | 70.1 | 3316 | 90.4 | 3355 | 91.5 |
Number of participants who agreed to link their data to other health studies and registries and number who agreed to DNA analyses.
1Refers to samples 1-5 in the float chart (Figure 1);
21193 individuals did not take part in the baseline study in 2001 (935 were new individuals and 258 individuals took part in a similar study in 2000). This explains why there are 1193 less individuals invited to the follow-up of the Oslo, school-based, as compared with the cross-sectional, school-based;
3173 individuals out of 3811, who participated in the baseline survey in Oslo in 2001 and were not on school lists in 2004, did not consent to a new invitation, in addition 61 had unknown address, thus 1084 were invited by post to the follow-up in 2004;
4229 individuals out of 1939 who participated in the baseline survey in Hedmark in 2001 did not consent to a new invitation, in addition 27 had unknown address, thus 1683 were invited in 2004.