Table 1 Overview of measurement points and available and future data
| Â | PIER-study database (already collected) | PIERYOUTH | ||
|---|---|---|---|---|
T1 10/2011–03/2012 | T2 10/2012–03/2013 | T3 10/2014–03/2015 | T4a 08/2022–08/2023 | |
N (children) | 1657 | 1612 | 1534 | 1074 |
Drop-out rate (from the previous assessment point) | – | 3% | 5% | 30% |
Age (M ± SD; Range) in years | 8.36 ± 0.95; 6–10 years | 9.11 ± 0.93; 7–11 years | 11.06 ± 0.92; 9–13 years | 17.91 ± 1; 16–21 years |
% female | 52% | 52% | 52% | 52% |
N (parents) | 1340 | 1197 | 1070 | 750 |
N (teachers) | 1424 | 1175 | 1113 | will no longer be assessed |