National Farm Medicine Center, Marshfield Clinic Research Foundation, Marshfield, WI 54449, USA.
Pediatrics. 2011 Nov;128(5):e1139-46. doi: 10.1542/peds.2011-0770. Epub 2011 Oct 10.
We had the rare opportunity to conduct a cluster-randomized controlled trial to observe the long-term (16-year) effects of a well-designed hearing conservation intervention for rural high school students. This trial assessed whether the intervention resulted in (1) reduced prevalence of noise-induced hearing loss (NIHL) assessed clinically and/or (2) sustained use of hearing protection devices.
In 1992-1996, 34 rural Wisconsin schools were recruited and 17 were assigned randomly to receive a comprehensive, 3-year, hearing conservation intervention. In 2009-2010, extensive efforts were made to find and contact all students who completed the original trial. Participants in the 16-year follow-up study completed an exposure history questionnaire and a clinical audiometric examination. Rates of NIHL and use of hearing protection were compared.
We recruited 392 participants from the original trial, 200 (53%) from the intervention group and 192 (51%) from the control group. Among participants with exposure to agricultural noise, the intervention group reported significantly greater use of hearing protection compared with the control group (25.9% vs 19.6%; P = .015). The intervention group also reported significantly greater use of hearing protection for shooting guns (56.2% vs 41.6%; P = .029), but the groups reported similar uses of protection in other contexts. There was no significant difference between groups with respect to objective measures of NIHL.
This novel trial provides objective evidence that a comprehensive educational intervention by itself may be of limited effectiveness in preventing NIHL in a young rural population.
我们有幸开展了一项集群随机对照试验，以观察为农村高中生精心设计的听力保护干预措施的长期（16 年）效果。该试验评估了干预措施是否导致（1）临床评估的噪声性听力损失（NIHL）患病率降低，和/或（2）听力保护装置的持续使用。
1992 年至 1996 年，我们招募了 34 所威斯康星州农村学校，其中 17 所被随机分配接受为期 3 年的综合性听力保护干预。2009 年至 2010 年，我们做出了大量努力寻找并联系所有完成原始试验的学生。参加 16 年随访研究的参与者完成了一份暴露史问卷和临床听力检查。比较了 NIHL 的发生率和听力保护的使用情况。
我们从原始试验中招募了 392 名参与者，其中干预组 200 名（53%），对照组 192 名（51%）。在接触农业噪声的参与者中，干预组报告的听力保护使用率明显高于对照组（25.9%对 19.6%；P=0.015）。干预组还报告称，在射击枪支时，他们更倾向于使用听力保护设备（56.2%对 41.6%；P=0.029），但两组在其他情况下的保护设备使用率相似。两组的客观 NIHL 测量结果没有显著差异。
这项新颖的试验提供了客观证据，表明单纯的综合性教育干预本身可能对预防农村年轻人群的 NIHL 效果有限。
