Cohort demographics and risk factors (continuous variables, mean (SD))
| Characteristic | Apprentices (n = 374) | Students (n = 62) | Total (n = 436) |
|---|---|---|---|
| Demographic factors | |||
| Age | 27.2 (7.0) | 27.2 (4.2) | 27.2 (6.7) |
| Noise exposure factors | |||
| Construction work (years) | 2.2 (3.2) | 0.2 (0.8) | 1.9 (3.1) |
| Non-construction noisy work (years) | 3.8 (6.0) | 3.4 (4.8) | 3.7 (5.9) |
| Regular firearm use (years) | 2.2 (5.1) | 0.0 (0) | 1.9 (4.8) |
| Firearms/explosion in military (years) | 0.2 (1.0) | 0.01 (0.06) | 0.2 (0.9) |
| Power tool use (hours/week) | 2.2 (4.1) | 0.4 (0.5) | 2.0 (3.9) |
| Home machinery use (years) | 0.5 (2.8) | 0.1 (0.6) | 0.5 (2.6) |
| Machine use in military (years) | 0.4 (1.8) | 0.2 (1.0) | 0.4 (1.7) |
| Motorcycle use (years) | 2.1 (4.8) | 0.1 (0.5) | 1.8 (4.5) |
| Other exposure factors | |||
| Solvent exposure (years) | 1.3 (3.4) | 0.9 (2.1) | 1.3 (3.2) |
| Paint exposure (years) | 0.5 (1.6) | 0.0 (0.1) | 0.4 (1.5) |