Table 3.
The results of linear mixed model analysis for hearing loss at different frequencies
| Hearing threshold | 250 Hz (p-value) |
500 Hz (p-value) |
1000 Hz (p-value) |
2000 Hz (p-value) |
4000 Hz (p-value) |
8000 Hz (p-value) |
|---|---|---|---|---|---|---|
| Variables | ||||||
| Work experience (years) | 1.83 (˂0.001) |
1.66 (˂0.001) |
1.32 (˂0.001) |
1.20 (˂0.001) |
1.90 (˂0.001) |
1.32 (˂0.001) |
| Initial hearing threshold | 0.7368 (˂0.001) |
0.7711 (˂0.001) |
0.7308 (˂0.001) |
0.6848 (˂0.001) |
0.6397 (˂0.001) |
0.6176 (˂0.001) |
| Age at employment | - | - | -0.4136 (0.340) |
-0.0841 (0.085) |
- | -0.1801 (˂0.001) |
| BMI | 0.0661 (0.257) |
- | 0.5393 (0.040) |
- | - | - |
| Systolic blood pressure | - | - | -0.2418 (0.033) |
- | - | - |
| Diastolic blood pressure | - | - | -2.64 (0.042) |
- | - | - |
| Smoking | 0.2457 (0.452) |
- | 0.1918 (0.519) |
- | - | -0.0079 (0.986) |
| Basic hearing threshold × work experience | -0.0598 (˂0.001) |
-0.0604 (˂0.001) |
-0.0553 (˂0.001) |
-0.0562 (˂0.001) |
-0.0347 (˂0.001) |
-0.0434 (˂0.001) |
| work experience × age at employment | - | - | 0.0134 (0.055) |
0.0174 (0.05) | - | 0.0456 (˂0.001) |
| work experience × smoking | -0.1183 (0.033) | -0.0970 (0.040) |
- | - | -0.2024 (0.04) |
|
| Diastolic blood pressure × Age at employment | - | - | 0.1050 (0.039) |
- | - | - |
| Age at employment × BMI | -0.0021 (0.175) | - | - | - | - | - |
| Subject random intercept var (SD) | 0.0980 (0.3283) | 0.2336 (0.4833) | 0.1826 (0.4274) |
0.0415 (0.2038) | 0.0547 (0.2338) | 0.0812 (0.2849) |
| Subject random slope var (SD) | 0.1077 (0.3130) |
0.1331 (0.3649) | 0.0734 (0.2709) |
0.1487 (0.3856) | 0.3363 (0.5799) | 0.4373 (0.6613) |
| Residual var (SD) | 15.52 (3.94) |
15.84 (3.98) |
12.47 (3.53) |
13.74 (3.70) |
24.93 (4.99) | 30.96 (5.56) |