ABSTRACT
Public health continues to be beset by debate over the quality of epidemiological studies and the data they generate. Epidemiology's association with public health has continued to the present day, following the rapid expansion of the discipline following the Second World War. The emphasis in epidemiology on methodology and empirical observations has also led to charges of the discipline being 'atheoretical'. In order to be able to evaluate these arguments some understanding of the character and purposes of epidemiology and its relationship with public health is required. The rise of chronic degenerative diseases, themselves a manifestation of living longer, has been accompanied by a shift in focus within epidemiology towards the study of individual risk factors: genetic, biological and behavioural. Experimental studies are better able to test hypotheses than observational studies and can provide stronger evidence of causality if properly carried out with sufficiently large sample sizes to detect real differences between groups studied.
