Descriptive studies, cohort studies, case-control studies, cross-sectional studies, and ecological studies were briefly discussed in the last slide. These study designs are investigation and exposure assessment tools fundamental to all branches of epidemiology. They are not recent epidemiologic advances but are included here primarily for completeness only. Further elaboration on their use in epidemiology can be found in recent textbooks (Gordis, 1996; Lilienfeld and Stolley, 1994; Rothman and Sander, 1998; Szklo and Nieto, 2000).

Both the International Society for Pharmacoepidemiology (ISPE, 1996) and the International Epidemiological Association (IEA, 2000) have provided sound guidance for good epidemiology practices. The guidance document provided by ISPE is more on practices for drug, device, and vaccine research, whereas the IEA guidance has a focus on competence criteria for use to qualify a well-trained epidemiologist. To date, World Health Organization (WHO, 1983) has provided the most comprehensive guidance document for use of epidemiologic studies within the context of health risk assessment (RA). This WHO document, entitled “Guidelines on Studies in Environmental Epidemiology”, was coincidentally published in the year the RA scheme was first formulated by the National Research Council (1983).

The WHO document covered not only the various basic epidemiologic study designs mentioned above, but also such topics as assessment of exposure and adverse health effects. As discussed in Lecture 3, human exposure assessment and hazard identification are two of the four key components of RA.