Analysis of approaches to the formation of a control group in radon epidemiological case-control studies

Objectives: Studying the influence of the method of selecting a control group in the radon case-control study on assessment of dose-effect dependence. Study the effect of additional additive or multiplicative risk factors on the results of the study. Materials and Methods: Simulation of a large-scale radon epidemiological case-control study. Analyzing of the influence of the representative value of the comparison subgroup on the results of calculating the odds ratio of the incidence of radiation-induced lung cancer. Analysis of different variants of standardization of the control group on the correctness of the dose-effect dependence. Development of methods for identifying risk factors that affect the incidence of lung cancer and determining the mechanism of their influence (additive or multiplicative). Results: It is shown that the insufficient representativeness of the comparison subgroup used in calculating the odds ratio can significantly distort the estimates of dose-effect dependence. In the presence of factors (sex, smoking, etc.), correlating both with the incidence of lung cancer and of radon concentration, complete standardization of such factors is necessary. Multiplicative risk factors without such correlation do not require additional standardization in the selection of a control group. Calculation of the odds ratio for various risk factors in subgroups differing in the levels of spontaneous cancer incidence allows to determine the significance of this factor for the incidence of lung cancer, and to establish the preferential mechanism of the influence of this factor (multiplicative or additive). Conclusions. When carrying out the radon case-control study, it is necessary to identify risk factors that correlate both with the incidence of lung cancer, and with the radon concentration, to assess the mechanism of action of these factors and to made the complete standardization of the control group for them.

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