Summary of findings 7. Well‐implemented hearing loss prevention programme (HLPP) compared to less well‐implemented HLPP (hearing loss).
| Well‐implemented hearing loss prevention programme (HLPP) compared to less well‐implemented HLPP for hearing loss | ||||||
| Patient or population: workers Settings: exposure to noise Intervention: well‐implemented HLPP Comparison: less well‐implemented HLPP | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Less well‐implemented HLPP | Well‐implemented HLPP | |||||
| Hearing loss STS > 10 dB change average over 2, 3 and 4 kHz1 Follow‐up: mean 9.3 years | 86 per 1000 | 36 per 1000 (21 to 61)2 | OR 0.40 (0.23 to 0.69)3 | 16,301 (3 studies4) | ⊕⊝⊝⊝ very low5 | SMD 0.26 (0.14 to 0.47) |
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; HLPP: hearing loss prevention programme; OR: Odds ratio; STS: standard threshold shift | ||||||
| GRADE Working Group grades of evidence High quality: we are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of effect, but there is a possibility that it is substantially different Low quality: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect Very low quality: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect | ||||||
1STS used in two studies, change of mean 4 kHz threshold in one study. 2Number of events based on median event rate in included studies. 3Result from the meta‐analysis of three studies. 4One extra study provided similar evidence but could not be combined in the meta‐analysis. 5We downgraded by one level from low to very low because of risk of bias due to lack of adjustment for age and hearing loss.