Application of the Intensity Normalization Indicators method for predicting occupational morbidity in leading industries

Abstract

Introduction. Identification of risk factors for the occurrence of occupational diseases by comparing various prognostic criteria is one of the most important tasks of hygiene and occupational health. The purpose of the study is to develop a prognostic matrix of occupational morbidity (OM) in the leading industries of the Irkutsk region for a set of main predictor factors using the method of intensity normalization indicators (INI). Materials and methods. There was used an information array of long-term OM in the leading industries of the Irkutsk region. The method of calculating weight indices was used to assess the strength of the influence of OM predictor factors and the INI method was used to calculate the prognostic significance of the factors. Results. The risk of occupational disease (OD) has been established to be associated with belonging to a certain occupation (OR=61.8), combined exposure to harmful factors in the working environment (OR=23.8), due to the imperfection of the technological process and equipment. The work experience with a harmful occupational factor, the age of employee, the industry are also significant, but the degree of their influence on the occurrence of OD is much lower. Based on the predictor factors, the risk of OD was calculated, its possible range (0.019-0.412 conventional units) with three subranges (favourable, uncertain and unfavourable prognosis) was determined. The risks of OD in persons with a work experience of 1-4 years, under the age of 40, exposed to the combined effects of physical factors, working as excavator driver and an assembler-riveter, were 0.269 and 0.226 (uncertain forecast). The risk values of OD in workers of these occupations increase by 24.4% and 29.1%, respectively, with an increase in length of service and age, reaching a maximum at the age of 50-59 years with an work experience of 30 or more years (0.334 and 0.292, unfavourable prognosis). The limitations of this INI model include the non-inclusion of clinical, functional, biochemical and socio-psychological indicators of workers among the predictor factors. Limitations. An analysis of one thousand eight hundred sixty two cases of newly diagnosed occupational diseases over a 10-year period, 11 main predictor factors, which is a sufficient reference sample, was made to study occupational morbidity in the leading industries of the Irkutsk region and developing a prognostic matrix. Conclusion. The use of INI makes it possible to give an integrated risk assessment of the OD both for individual factors and for their complex, and to determine risk groups.