Table 1.
Demographic characteristics of study subjects.
| Variables | Case group (n = 380) | Control group (n = 380) | P | ||
|---|---|---|---|---|---|
| n | % | n | % | ||
| Age (years) | |||||
| Mean ± SD | 39.82 ± 6.59 | 40.09 ± 6.32 | 0.567a | ||
| Sex | |||||
| Male | 358 | 94.2 | 355 | 93.4 | 0.652b |
| Female | 22 | 5.8 | 25 | 6.6 | |
| Tobacco use | |||||
| Now | 223 | 58.7 | 210 | 55.3 | 0.501b |
| Ever | 9 | 2.4 | 13 | 3.4 | |
| Never | 148 | 38.9 | 157 | 41.3 | |
| Alcohol consumption | |||||
| Now | 169 | 44.5 | 173 | 45.5 | 0.836b |
| Ever | 8 | 2.1 | 10 | 2.6 | |
| Never | 203 | 53.4 | 197 | 51.8 | |
| Work time with noise (years) | |||||
| Mean ± SD | 17.35 ± 7.60 | 16.94 ± 7.16 | 0.452a | ||
| Expose level with noise (dB) | |||||
| Mean ± SD | 89.52 ± 7.26 | 90.09 ± 6.98 | 0.269a | ||
| High-frequency hearing threshold (dB) | |||||
| Mean ± SD | 36.74 ± 10.23 | 13.66 ± 4.20 | <0.001 c | ||
| ≤25 | 0 | 0.0 | 380 | 100.0 | |
| >25 | 380 | 100.0 | 0 | 0.0 | |
aStudents' t-test. bTwo-sided χ2 test. cFisher's exact test.