The analysis of the relationship between those parameters used to measure risk and those used to measure efficiency of diagnostic or screening tests is used, in this paper, to demonstrate the limitations of the use of risk factors as predictors of outcomes distribution in a population. The issue was illustrated by the study of the association, in children, of reported bathing in rivers by asking children if they bathed in rivers and the occurrence of Schistosoma mansoni infection. This question […]

The mortality ratios: the standardized risk ratio (SRR), the standardized mortality ratio (SMR), and the standardized proportional mortality ratio (SPMR) are presented with the purpose of disseminating a methodology for the study of the mortality associated with occupational categories and social classes. The influence of the “Healthy Worker Effect” and of the “Inequality Effect” in the choice of the reference population is disucussed. An operational means of testing the statistical significance of these ratio is also presented.