Occupational Noise-Induced Hearing Loss in Iran: A Systematic Review and Meta-Analysis

A large portion of Iranian Working Population (IWP) is becoming at risk of Occupational Noise-Induced Hearing Loss (ONIHL). Several primary studies have evaluated the prevalence of ONIHL in Iran with a variety of prevalence rates. We aimed to estimate the prevalence of ONIHL in the IWP using data from relevant studies.

The present study is a meta-analysis and systematic review of previously published studies on ONIHL in Iran. Accordingly, the relevant articles published until Sep 1, 2021 were searched through PubMed, Scopus, and Google Scholar, together with Iranian scientific electronic databases. Heterogeneity between among the studies and data analysis was assessed using the I2 test and Random-Effect Model (REM) respectively.

Having performed a quality assessment, the meta-analysis was performed on the data from twenty-six studies involving a total of 85685 participants. The prevalence of ONIHL was observed to range from 12.9% to 60.5% in the reviewed studies. Moreover, after combining the results from the primary research by the Random Effects Model (REM) approach, the prevalence of ONIHL among IWP was estimated to be 34.69% (95% CI: 29.10, 40.28).

ONIHL is a significant concern with regard to public and occupational health in Iran. The results also highlighted the urgent need for taking appropriate preventive and control measures in the workplaces; particularly by encouraging the employers and health-related policymakers to focus on preventive noise control techniques along with administrative and legislative approaches to mitigate the risk of developing ONIHL.