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.
Mortality rate; Epidemiology methods; Occupations; Social class; Risk
