An edited reposting!
Did you know that there is a whole science behind causation? It started way back in the later 1800's when Robert Koch formulated his postulates to persuade his contemporaries that the he had found the cause of tuberculosis.
His postulates are:
1. The specific organism should be shown to be present in all cases of animals suffering from a specific disease but should not be found in healthy animals.
2. The specific microorganism should be isolated from the diseased animal and grown in pure culture on artificial laboratory media.
3. This freshly isolated microorganism, when inoculated into a healthy laboratory animal, should cause the same disease seen in the original animal.
4. The microorganism should be reisolated in pure culture from the experimental infection.
Kochs's postulates served us well, but broke down when we tried to apply them to viruses that only have one host. It then fell to the British Statistician, Sir Austin Bradford-Hill, to formulate more general and appropriate criteria of causation; the following are the Bradford-Hill criteria:
1. CONSISTENCY AND UNBIASEDNESS OF FINDINGS
2. STRENGTH OF ASSOCIATION
3. TEMPORAL SEQUENCE
4. BIOLOGICAL GRADIENT (DOSE-RESPONSE RELATIONSHIP)
6. COHERENCE WITH BIOLOGICAL BACKGROUND AND PREVIOUS KNOWLEDGE
7. BIOLOGICAL PLAUSABILITY
8. REASONING BY ANALOGY
9. EXPERIMENTAL EVIDENCE
If you are interested in reading about these criteria I suggest the following references:
Bradford-Hill A. The environment and disease: association or causation? Proc Royal Soc Med 1965; 58:295-300.
Bradford-Hill's criteria have also been modified to apply them to the problem of MS:
Giovannoni et al. Infectious causes of multiple sclerosis.Lancet Neurol. 2006 Oct;5(10):887-94.
"When you apply Bradford-Hill's criteria to CCSVI, the majority of the boxes, cannot be ticked. In addition, in light of new data the entity of CCSVI is questionable."
"Does CCSVI exist as a definite entity?"
"Is CCSVI the biggest fraud in the history of MS?"
"Who is responsible for the deaths of the MSers who died having unproven therapies that are not been done under an ethically approved clinical protocol?"
"Is is ethical to enroll MSers into invasive trials when the condition is unlikely to exist?"
"Is Zamboni a fraud?"
"Should Zamboni's University investigate the integrity of his research?"
"Why didn't Zamboni disclose his conflicts of interests?
"Should Zamboni disclose what he has gained financially from CCSVI?"
"Why are the NICE, ECTRIMS and FDA guidelines on CCSVI being ignored?"
"Is it appropriate for charities and governments to be spending vast sums of money on CCSVI research when the unmet research need is so great in other areas of MS research?"
"These are all important questions that need an answer!"
Labels: Bradford-Hill, causation, CCSVI