Objectives: Numerous epidemiological studies have provided some evidence indicating that workers employed in the pulp and paper industry are at higher risk of death from lung cancer. The present study was undertaken to analyze lung cancer risk prediction among male workers employed in this industry.
Materials and methods: To estimate the probability of death from lung cancer a risk prediction model with some elements of competing risks was used. The risk assessment was based on the cohort study data collected in workers involved in pulp and paper production.
Results: Four exposure-response relationship curves were developed adopting the age at the first occupational exposure as a criterion. The model based on the competing risk theory rendered it possible to estimate an additional risk of lung cancer related to a specific period of occupational exposure for the groups adjusted by the age of entering the cohort. For example, in the group with first exposure at the age below 29, the risk changed from 2.25 x 10(-7) during the first year of employment to 1.40 x 10(-5) after 10 years, whereas in the group of workers with first exposure at the age of 50 years, the risk changed from 6.42 x 10(-5) to 4.28 x 10(-4). In addition, the risk at first exposure at the age of 50-59 was almost two orders of magnitude higher than that in workers with first exposure at the age below 29 (6.42 x 10(-5) and 2.25 x 10(-7), respectively).
Conclusions: Using the additional (absolute) risk model involving elements of competing risk theory it is possible to provide a more thorough characteristics of the relationship between the exposure level and probability of death from lung cancer.