234104 Creating and dissecting causality issues for non-acute or complex diseases

Monday, November 8, 2010 : 1:20 PM - 1:45 PM

Stanley H. Weiss, MD, FACP, FACE , Department of Preventive Medicine & Community Health, UMDNJ - New Jersey Medical School, and UMDNJ - School of Public Health, Newark, NJ
Is there a crisis in medicine and public health with regard to inadequate understanding of causality issues in the modern era? Koch's postulates are well known. They serviced us well when trying to assess whether an infectious agent (which were usually then bacterial or fungal species) caused a single, acute disease. This simple approach frequently fails when dealing with more complex phenomena, such as multi-factorial diseases, illnesses with step-wise development, or most viruses or novel infectious agents. Similarly, whereas many laboratory investigations focus on studying a single pathway in vitro, biology frequently involves feedback loops (positive or negative) and multiple or alternative pathways. Thus, in vivo phenomena may severely deviate from inferences and expectations based on initial research. This may help to explain some of the recent prominent failures of new drugs under development and controlled clinical trials, and discrepancies among results from cross-sectional, case-control and cohort epidemiologic study designs and/or clinical trials. Furthermore, genetic variations may lead to varying degrees of side effects, some of which may be rare and thus only discerned after widespread usage of a drug. The balancing of benefits and harm can be much more complicated for populations than for individuals, and varying indications and warnings can be problematic issues.

Learning Areas:
Basic medical science applied in public health
Biostatistics, economics
Public health biology
Public health or related research
Systems thinking models (conceptual and theoretical models), applications related to public health

Learning Objectives:
Know the limitations of Koch's postulates. Apply modern inference approaches regarding causality, especially in the setting of non-acute disease or multifactorial causation. Better understand why divergences may occur amongst studies of various designs, especially case-control and prospective cohort epidemiologic studies and controlled clinical trials.

Keywords: Epidemiology, Chronic Diseases

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: have lectured on this topic at international epidemiology meetings as well as to students, and have organized past symposia on these issues
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

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