Table 2.
Distributions of independent variables and results of bivariate analysis (prevalence of abnormal hearing test results, in either ear and both ears, at different levels of independent variables) in three factories in Thailand
| Independent variable | Distribution, n (%), total=180 | Bivariate analysis of hearing test results | |||
|---|---|---|---|---|---|
| Abnormal in either ear | Abnormal in both ears | ||||
| Prevalence, n (%) | p-value | Prevalence, n (%) | p-value | ||
| *Variable entered in interim logistic regression model of either ear †Variable entered in interim logistic regression model of both ears | |||||
| Noise level (dB (A))*† | <0.001 | <0.001 | |||
| <86 | 67 (37.2) | 4 (9.5) | 2 (13.3) | ||
| ≥86-90 | 96 (53.3) | 25 (59.5) | 7 (46.7) | ||
| >90 | 17 (9.4) | 13 (31.0) | 6 (40.0) | ||
| Pack-year smoking*† | 0.001 | <0.001 | |||
| <10 | 162 (90.0) | 32 (76.2) | 8 (53.3) | ||
| ≥10 | 18 (10.0) | 10 (23.8) | 7 (46.7) | ||
| Duration of employment (years)* | 0.095 | 0.623 | |||
| <10 | 141 (78.3) | 29 (69.0) | 11 (73.3) | ||
| >10 | 39 (21.7) | 13 (31) | 4 (26.7) | ||
| Age (years) * | 0.031 | 0.207 | |||
| 20-30 | 49 (27.2) | 6 (14.3) | 2 (13.3) | ||
| >30-50 | 131 (72.8) | 36 (85.7) | 13 (86.7) | ||
| Previous earplug use | 0.750 | 0.807 | |||
| No | 165 (91.7) | 38 (90.5) | 14 (93.3) | ||
| Yes | 15 (8.3) | 4 (9.5) | 1 (6.7) | ||
| Music ear buds use | 0.290 | 0.787 | |||
| No | 90 (50.0) | 24 (57.1) | 8 (53.3) | ||
| Yes | 90 (50.0) | 18 (42.9) | 7 (46.7) | ||
| Group* | 0.170 | 0.520 | |||
| Factory A | 60 (33.3) | 11 (26.2) | 4 (26.7) | ||
| Factory B | 60 (33.3) | 19 (45.2) | 7 (46.7) | ||
| Factory C | 60 (33.3) | 12 (28.6) | 4 (26.7) | ||
| Job position* | 0.030 | 0.339 | |||
| Leader | 42 (23.3) | 15 (35.7) | 2 (13.3) | ||
| operator | 138 (76.7) | 27 (64.3) | 13 (86.7) | ||
| Education level*† | 0.156 | 0.101 | |||
| Junior High School | 59 (32.8) | 13 (31.0) | 2 (13.3) | ||
| Senior High School | 65 (36.1) | 20 (47.6) | 9 (60.0) | ||
| ≥Vocational Certificate up | 56 (31.1) | 9 (21.4) | 4 (26.7) | ||
| Noise level perception in current job | 0.823 | 0.558 | |||
| Low | 83 (46.1) | 20 (47.6) | 8 (53.3) | ||
| High | 97 (53.9) | 22 (52.4) | 7 (46.7) | ||
| Noise level perception in previous job | 0.876 | 0.290 | |||
| Low | 109 (60.6) | 25 (59.5) | 11 (73.3) | ||
| High | 71 (39.4) | 17 (40.5) | 4 (26.7) | ||