Russian Journal of Occupational Health and Industrial Ecology · Oct 8, 2026

Medium-term clinical and economic outcomes of a multi-course medical preventive programme for machine-building plant workers exposed to occupational noise

By Fayzova YM, Fatkhutdinova LM

Introduction. A shortage of skilled workers increases the relevance of programmes aimed at extending occupational longevity for employees with early signs of exposure to occupational hazards, including noise. However, evidence of the effectiveness of such programmes is limited.The aim of the study is to evaluate the medium-term clinical and economic outcomes of a medical preventive programme for machine-building plant workers with early signs of occupational noise exposure.Materials and methods. A historical closed cohort of 113 workers (mean age 55.8 years, work experience 26.1 years, equivalent sound level 89.7 dBA) was followed up from 2013 to 2025. Workers received two or three courses of the medical preventive programme (median duration 4 years) between 2013 and 2023. Shifts and rates of shift in hearing thresholds at frequencies of 500, 1000, 2000, and 4000 Hz, as well as the binaural pure tone average (BPTA), were assessed using linear mixed-effects models. The rate of threshold shift was compared with the age-related reference vales of ISO 7029-2017, and the number of cases of occupational noise-induced hearing loss (ONIHL) assessed against that predicted by the ISO 1999‑2017 model and the comparison group (113 workers selected using a matched-pair design). A scenario-based calculation of the benefit-cost ratio (BCR) was carried out using the modified human capital approach.Results. Hearing thresholds increased at all frequencies; at 2000 and 4000 Hz, as well as for BPTA, not statistically significant. The rate of threshold shift was below the expected at 4000 Hz (–1.06 dB/year; 95% CI –1.76…–0.35; p=0.003) and for BPTA (–0.38 dB/year; 95% CI –0.71…–0.05; p=0.024). The result was robust in sensitivity analysis. Over 12 years, no cases of ONIHL with loss of occupational working capacity were registered, compared with 10.4 expected by the model and one case in the comparison cohort. The prevalence of cardiovascular diseases rose from 41.6% to 54.9% (p<0.001). Payback is achieved by preventing approximately 2 cases of occupational working capacity per 100 employees.Limitations. The observational design without an external control group limited the ability to separate the contribution of the intervention from the natural course of the disease. The small number of ONIHL cases reduced the statistical power of the comparisons. The study evaluated the effect of a package of measures rather than individual interventions. The economic calculation was scenario-based.Conclusions. Among workers who completed a two- or three-course medical preventive programme, the rate of hearing threshold shifts at 4 kHz and by BPTA was below the expected changes. The programme proved to be potentially cost-effective. The rise in cardiovascular morbidity indicates the need to integrate measures for cardiometabolic risk factors correction. The findings require confirmation in a prospective study.Ethics. The study was conducted in accordance with the principles of the Declaration of Helsinki; all participants provided written informed consent.Contributions:Fayzova Yu.M. — collection and processing of material, data processing, text writing;Fatkhutdinova L.M. — study concept and design, data processing, text writing;All authors — approval of the final version of the article, responsibility for the integrity of all parts of the article.Funding. The study had no financial support.Conflict of interest. The authors declare the absence of any apparent or potential conflicts of interest related to the publication of this article.Received: 29.09.2026 / Accepted: 30.09.2026 / Published: 09.10.2026

doi.org/10.31089/1026-9428-2026-66-9-577-588 Open access Interventions