1. Recalculation of study data for review results and meta‐analysis.
| Küpper 2013 (Outcome: Leq 8 h (dB)a) ‐ noise exposure of rescue helicopter personnel ‐ case study | ||||||||||
| Study data | Recalculation ‐ group mean, SD | |||||||||
| Helicopter type | Helicopter name | mean | SD | dB min | dB max | variance | mean | SD | ||
| with advanced technology | EC 135b | 85.80 | 4.00 | 73.00 | 97.00 | 16.00 | 87.9 | 4.16 | ||
| BK 117b | 87.20 | 4.60 | 74.00 | 101.00 | 21.16 | |||||
| Bell 206 B Jetrangerc | 88.80 | 4.00 | 76.00 | 100.00 | 16.00 | |||||
| Bell 206 Longranger IIc | 89.80 | 4.00 | 77.00 | 101.00 | 16.00 | |||||
| without advanced technology | UH 1Db | 86.80 | 4.00 | 74.00 | 98.00 | 16.00 | 98.41 | 4.49 | ||
| BO 105c | 91.80 | 4.00 | 79.00 | 103.00 | 16.00 | |||||
| Sea Kingc | 92.60 | 7.50 | 78.00 | 114.00 | 56.25 | |||||
| Ecureuil AS350Bb | 92.80 | 4.00 | 80.00 | 104.00 | 16.00 | |||||
| Alouette IIIbb | 98.40 | 4.80 | 85.00 | 113.00 | 23.04 | |||||
| Sikorsky H‐23/UH12c | 99.70 | 3.90 | 87.00 | 111.00 | 15.21 | |||||
| Alouette IIb | 100.10 | 4.40 | 87.00 | 113.00 | 19.36 | |||||
| Sikorsky H‐34c | 101.8 | 4.00 | 89.00 | 113.00 | 16.00 | |||||
| Mi‐4c | 109.10 | 3.50 | 97.00 | 117.00 | 12.25 | |||||
| Sikorsky H‐37 Mojavec | 111 | 3.40 | 99.00 | 119.00 | 11.56 | |||||
| Muhr 2016 (Outcome: STS) ‐ hearing loss Swedish military ‐ CBA | ||||||||||
| Study data | Recalculation | |||||||||
| group | follow up mean (month) | # Events | N | follow up (month/year) | per 100 person‐years | |||||
| event rate | lnRR | SE | ||||||||
| HLPP | 8 | 9 | 395 | 0.67 | 3.4 | 0.002 | 0.379 | |||
| non‐exposed | 13 | 31 | 839 | 1.08 | 3.4 | |||||
| Muhr 2006 (Outcome: STS) ‐ hearing loss Swedish military ‐ CBA | ||||||||||
| Study data | Recalculation | |||||||||
| group | follow up mean (month) |
# Events | N | group | follow up (year) |
# Events | N | per 100 person‐years | ||
| event rate | lnRR | SE | ||||||||
| HLPP (low‐exposed) | 9.25 | 11 | 291 | HLPP (low‐exposed) | 0.77 | 11 | 291 | 4.9 | 0.73 | 1.04 |
| HLPP (medium‐exposed) | 13 | 252 | non‐exposed (split 1) | 0.92 | 1 | 46 | 2.37 | |||
| HLPP (high‐exposed) | 35 | 204 | HLPP (medium‐exposed) | 0.77 | 13 | 252 | 6.69 | 1.04 | 1.04 | |
| non‐exposed | 11 | 4 | 138 | non‐exposed (split 2) | 0.92 | 1 | 46 | 2.37 | ||
| HLPP (high‐exposed) | 0.77 | 35 | 204 | 22.26 | 1.55 | 0.73 | ||||
| non‐exposed (split 3) | 0.92 | 2 | 46 | 4.74 | ||||||
| non‐exposed (all) | 0.92 | 4 | 138 | 3.16 | ||||||
| low‐exposed vs non‐exposed (all) | 0.439 | 0.584 | ||||||||
| medium‐exposed vs non‐exposed (all) | 0.750 | 0.572 | ||||||||
| high‐exposed vs non‐exposed (all) | 1.951 | 0.528 | ||||||||
aBased on task analysis and helicopter noise data, task analysis is based on measurements of type and duration of tasks per rescue operation of four bases over 1 year (total, 2726 rescue operations). bStudy authors obtained helicopter noise data from own measurements (n = 3 per helicopter). cStudy authors obtained helicopter noise data from other studies.