Subject selection for longitudinal analysis
| Apprentices | Controls | Total | ||||
|---|---|---|---|---|---|---|
| Subjects | Ears | Subjects | Ears | Subjects | Ears | |
| *Exclusions for middle ear problems or DPOAE data quality problems. | ||||||
| Included in baseline analysis | 372 | 720 | 62 | 120 | 434 | 840 |
| With 1 follow up | 276 | 536 | 60 | 116 | 336 | 652 |
| With 2 follow ups | 228 | 445 | 56 | 108 | 284 | 553 |
| With 3 follow ups | 169 | 331 | 52 | 101 | 221 | 432 |
| Excluded* | 8 | 18 | 0 | 2 | 8 | 20 |
| Included in current analysis | 268 | 518 | 60 | 114 | 328 | 632 |