Table 2.
Significant determinants of significant threshold shift (STS) in 226 Navy personnel from the Royal Norwegian Navy (RNoN), measured in two consecutive audiometric examinations between 2012 and 2014
| Determinant | Total | STSa | No STS | |||
|---|---|---|---|---|---|---|
| n | n (%) | n (%) | RRb | 95% CIc | ||
| “Have you had temporary reduced hearing, fullness, or ringing in the earsd after being exposed to noise in the Navy during the last 12 months?”e | 0 (ref) | 178 | 37 (20.8) | 141 (79.2) | 1 | |
| 1-5 | 24 | 5 (20.8) | 19 (79.2) | 1.00 | 0.44-2.30 | |
| > 5 | 23 | 10 (43.5) | 13 (56.5) | 2.09* | 1.21-3.62 | |
| “Are you currently in your work on board exposed to noise so loud that it is difficult to have a conversation?” | No, never (ref) | 32 | 7 (21.9) | 25 (78.1) | 1 | |
| <5 h/week | 142 | 30 (21.1) | 112 (78.9) | 0.97 | 0.47-2.00 | |
| 5-15 h/week | 36 | 7 (19.4) | 29 (80.6) | 0.89 | 0.35-2.26 | |
| >15 h/week | 16 | 8 (50.0) | 8 (50.0) | 2.29* | 1.01-5.18 | |
| “Number of gun shots (in the Navy, hunting and sports) during the last 12 months” | 0 (ref) | 44 | 5 (11.4) | 39 (88.6) | 1 | |
| 1-200 | 87 | 25 (28.7) | 62 (71.3) | 2.53* | 1.04-6.15 | |
| >200 | 95 | 22 (23.2) | 73 (76.8) | 2.04 | 0.83-5.03 | |
aSignificant threshold shift: Average change in hearing threshold ≥ + 10 dB at 2,000 Hz, 3,000 Hz, and 4,000 Hz in either ear, bRR = Relative risk, cCI = Confidence interval, dDefined as temporary threshold shift (TTS), eOne missing participant, *Statistical significance