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

Background: 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.

Methods: 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 Pub-Med, 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.

Results: 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).

Conclusion: 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 work-places; 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.