Nikpour Abolfazl, Gholami Fesharaki Mohammad
Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Iran J Public Health. 2022 Mar;51(3):669-675. doi: 10.18502/ijph.v51i3.8945.
There have been few reports on relationships between Shift Work (SW) and time to Noise-Induced Hearing Loss (NIHL). This research explores the relation between SW and time to NIHL among male workers.
Between 1990 and 2015, this historical cohort study was conducted. Two different definitions events (Low Frequency Hearing (LFH) and High Frequency Hearing (HFH)) of NIHL An average pure-tone hearing threshold was thresholds at 1, 1.5 and 2 kHz for LFH(un-normal>20) and 4, 6 and 8 kHz for HFH (un-normal>20) for Air (AC) and Bone (BC) conduction, in both ears, respectively. In this study Kaplan-Meier and Multilevel Cox Model in addition R version 3.2.1 and MLWiN software used to analysis data. -values less than 0.05 are considered to be statistically significant.
There were 6632 male workers in the research survey (mean age=35(±5)). Among these subjects, 2678 (40%),278 (4%) and 3676 (56%) were Day Workers (DW), Weekly Rotating Shift workers (WRS) and Routinely Rotating Shift workers (RRS), respectively. The result of this study showed more hazard risk of ear problem in LFH (Hazard=1.55 with 95% CI= (1.06-1.39)) and HFH (Hazard=1.08 with 95% CI= (1.04-1.13)) in RRS rather than day workers. In WRS group ear problem has been seen just in LFH (Hazard=1.55 with 95% CI= (1.2-2.0)).
The findings of the 15-year historical cohort study generally support a relationship between SW and time to NIHL. Therefore, more actions in the field of noise control, greater use of safety devices as well as increased staff training on the use of safety devices recommended for shift worker.
关于轮班工作（SW）与噪声性听力损失（NIHL）发生时间之间关系的报道较少。本研究探讨男性工人中SW与NIHL发生时间之间的关系。
在1990年至2015年期间进行了这项历史性队列研究。NIHL有两种不同的定义事件（低频听力（LFH）和高频听力（HFH））。平均纯音听力阈值分别为LFH（异常>20）时1、1.5和2kHz以及HFH（异常>20）时4、6和8kHz的气导（AC）和骨导（BC）阈值，双耳均如此。在本研究中，使用Kaplan-Meier和多水平Cox模型，此外还使用R版本3.2.1和MLWiN软件进行数据分析。P值小于0.05被认为具有统计学意义。
研究调查中有6632名男性工人（平均年龄=35（±5））。在这些受试者中，分别有2678名（40%）日班工人（DW）、278名（4%）每周轮班工人（WRS）和3676名（56%）常规轮班工人（RRS）。本研究结果显示，RRS组在LFH（风险=1.55，95%CI=（1.06-1.39））和HFH（风险=1.08，95%CI=（1.04-1.13））方面耳部问题的风险高于日班工人。在WRS组中，仅在LFH方面出现耳部问题（风险=1.55，95%CI=（1.2-2.0））。
这项为期15年的历史性队列研究结果总体上支持SW与NIHL发生时间之间的关系。因此，建议在噪声控制领域采取更多行动，更多地使用安全设备，并加强对轮班工人使用安全设备的培训。
