ABSTRACT
The estimation of health risks in epidemiology is most commonly performed using regression models with the aim of developing a realistic model of the system in question, to identify the variables of interest and to estimate the strength of their effect on a health outcome. This chapter discusses different methods for expressing the risks associated with exposures and their appropriateness given the type of study that is being performed. Epidemiology is the study of why and how often diseases occur in different groups of people. A key feature of epidemiology is the measurement of disease outcomes in relation to a population at risk. Data from epidemiological studies commonly consist of counts of disease in a defined geographical area and/or time-period, or of binary indicators of whether a subject is a case or control.
