General and Specific Causation Analyses
General Causation
General causation is the methodology by which scientists determine whether an agent is or is not capable of producing a particular disorder. In general, this requires evaluation of scientific/medical literature to identify dose-response relationships and documentation of medical conditions associated/caused by a specific agent.
ICTMs approach for a general causation analysis begins with a
- Review of literature from the ICTM library tailored to the specific allegations of a clients case;
- Search of current the scientific/medical literature to determine whether new studies have appeared that may be relevant;
- Analyze the strengths and weaknesses of the relevant literature;
- Assess the opposing expert’s literature for relevance or fit;
- Summarize the relevant literature for our clients rapid retrieval during depositions of opposing experts and cross-examination at trial.
Evaluation of the literature to establish a general causal link between adverse medical problems and exposure to an agent/drug requires application of epidemiological studies not simply case series or anecdotal reports. Analysis of the literature requires identification of human epidemiological studies that show a causal association with an adverse health effect. Such studies, published in recognized, peer-reviewed publications and with proper controls for confounding variables, provide valid data upon which scientists can rely in formulating causal conclusions and refuting unfounded rumors, beliefs, or biases.
Many general causation allegations are nothing more than untested theories. an untested theory can become a generally-accepted scientific fact only after the theory is tested, the methods and results of the test are published or presented in an appropriate manner, and the conclusions are accepted by a majority of scientists in the field. At ICTM we examine all of these issues when we determine whether a relationship between an agent and a disease has been scientifically established. We research literature thoroughly, weighing the strength of the data and the general acceptance of the proposed relationship. Because the scientific literature is continually changing and new studies are regularly published, and ICTM strives to tailor our evaluations to a clients needs, general causation analysis must be an ongoing process.
- Methodological Considerations these considerations include weight of evidence of the data, analytical bias of the study design and lack of control of confounding factors.
- Causation Criteria the following criteria taken from Sir A.B. Hill (1965), "The Environment and Disease: Association or Causation?" in Evolution of Epidemiologic Ideas are generally accepted in the medical/scientific community as being required to show causal relationships: strength of association, consistency in results among study conditions, specificity of effect location in the body, a temporal relationship, dose-response relationship, biological plausibility, Consistency of biology of the disease with established medical/scientific principles, consistency in results with animal studies, and similar associations observed with other, similar agents.
Specific Causation
Specific Causation establishes the nature and potential causes of the claimed medical conditions through:
- Abstraction and evaluation of medical records.
- Evaluation of potential alternative causes for the claimed injuries.
- Analysis of diagnostic errors, including highlighting failures of differential diagnosis.
- Distinguish between differential diagnosis and causation assessment. Perform both and determine whether opposing experts have done the same.
- Quantification of the exposure to the agent(s).
- Examination of temporal relationships.
