The main criticism that could be made to the logistic regression approach is that it is based on the asymptotic distribution of the LRT. In practice, the chi-square approximation is true only for large datasets. In the present paper we investigated the robustness of the logistic regression to different sample sizes and numbers of correction risk factors. We also aimed to compare how robustness is affected by the type of risk factors considered (qualitative or quantitative). The same investigations were performed with the corrected chi-square test to compare the robustness of the two approaches.