Introduction. In recent years, the Russian Federation has seen a steady gain in the incidence of chronic non-communicable diseases and temporary disability, which creates the preconditions for an increase in contraindications to work due to health reasons, which are the reason for establishing occupational unsuitability in workers.

The study aims. To study the structure of contraindications to work and the patterns of formation of professional unsuitability, identify risk factors for its development and rank them into 5 groups to develop criteria for the risk management system for occupational unsuitability.

Materials and methods. Based on the data of periodic medical examinations of one hundred twelve thousand five hundred forty six workers conducted in 2019–2023 at the Research Institute of Occupational Health, the structure of contraindications to work was established and risk factors for the development of professional suitability in workers were determined based on the analysis of 4,100 examinations. The objects of the study were workers of 29 occupations. The Pearson agreement criterion and relative risk indicуs were calculated.

Results. The proportion of employees who had contraindications to work and were considered unfit was 2.3%. A decrease in the proportion of those who are not qualified among all those who have passed the examination has been established from 62.9% to 19.9%. In 77.7% of cases, unsuitability was recognized as permanent, in 19.1% – temporary, in 3.2% of cases – the employee was recognized as fit to perform certain types of work. The average age of the unfit is 55.7±0.3 years. The highest proportion of unfit people was found among electricians (25.7%) and fitters of various profiles (21.4%). Most often, contraindications were detected due to contact with noise (24.4%) and when working at height (36.8%). Among those unsuitable, the average number of harmful production factors was established to be 4.80±0.31, the number of diseases detected in 1 worker was 5.8±0.06. Frequent contraindications (reasons for professional unsuitability) were eye diseases (48.3% of cases), ear diseases (18.6%), and diseases of the circulatory system (12.6%).

Limitations. The study is limited to the analysis of the results of occupational unsuitability examinations performed in the clinic of the Research Institute of Occupational Health in 2019–2023. These limitations allow planning further studies.

Conclusion. The results of the study are the basis for developing a ocupational unsuitability risk management system and aimed at introducing personalized prevention based on the results of periodic medical examinations.

Compliance with ethical standards. The study did not require the conclusion of the Ethics Committee.

Contribution: Bukhtiyarov I.V. — concept and design of the study; Zibarev E.V. — concept and design of the study, writing the text; Vostrikova S.M. — data collection and processing, writing the text; Kravchenko O.K. — data collection and processing, writing the text; Umnitsyna О.B. — data collection and processing, writing the text; Bessonova A.K. — data collection and processing;Mukhin K.S. — data collection and processing.All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Funding. The study had no sponsorship.

Received: April 23, 2025 / Accepted: June 26, 2025 / Published: September 25, 2025