| Methods |
CBA study |
| Participants |
Shots with 762 Rk 62 rifle
n = 5 shots
Finland
Military |
| Interventions |
Intervention: Hearing Protector Earmuffs: Peltor H61, Peltor H7, Peltor H6, Bilsom Marksman, Silenta Hunter at 156 Lcpeak dB(C); n = 5 |
| Outcomes |
Difference in noise level outside versus inside the protectors |
| Notes |
Immediate |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| 14. Blinding (subjects) |
High risk |
not blinded |
| 15. Blinding (outcome assessors) |
High risk |
not blinded |
| 16. Retrospective unplanned subgroup analyses |
Low risk |
no additional analysis |
| 17. Follow‐up |
Unclear risk |
immediate outcome measurement (inside/outside HPD) |
| 18. Statistical tests |
High risk |
no test used |
| 19. Compliance |
Low risk |
closely observed use of HPD |
| 20. Outcome measures |
Low risk |
calibrated measurements |
| 21. Selection bias (population) |
Unclear risk |
all subjects were military staff |
| 22. Selection bias (time) |
Low risk |
same day in 1995 |
| 23. Randomization |
High risk |
not randomised |
| 24. Allocation concealment |
Unclear risk |
not randomised, not applicable |
| 25. Adjustment for confounding |
Unclear risk |
not reported |
| 26. Incomplete outcome data |
Unclear risk |
not reported |
