Case Model: The Causation Rules of Althen
In its Althen decision, the United States Court of Appeals for the Federal Circuit established the legal rules that form the foundation for the Lab’s sample of Vaccine Act decisions.
In a case claiming compensation for loss of vision caused by a tetanus toxoid vaccination, the Court affirmed the judgment of the United States Court of Federal Claims that reversed the special master’s denial of the claim. In deciding the case, the Court formulated a three-pronged prima facie case for a petitioner who needs to prove causation in fact in an off-Table vaccine case. In the Court’s words:
“Concisely stated, Althen’s [the petitioner’s] burden is to show by preponderant evidence that the vaccination brought about her injury by providing: (1) a medical theory causally connecting the vaccination and the injury; (2) a logical sequence of cause and effect showing that the vaccination was the reason for the injury; and (3) a showing of a proximate temporal relationship between vaccination and injury.”
Althen, 418 F.3d at 1278. The Court then added:
“If Althen satisfies this burden, she is ‘entitled to recover unless the [government] shows, also by a preponderance of evidence, that the injury was in fact caused by factors unrelated to the vaccine.’”
Althen, 418 F.3d at 1278 (brackets in original).
These substantive legal rules form the foundation for the Lab’s inquiry in its Vaccine / Injury Project. We are investigating all of the subsequent decisions in which the special masters apply these rules to the evidence in particular cases, by modeling the factfinding reasoning of the special masters as they assess the evidence and make their findings on causation.
The following excerpt shows our model of the three-pronged substantive rule for the prima facie case on causation in fact, as established by the Althen case:
Finally, in rejecting an argument advanced by the government, the Court noted some policies important in evidence assessment:
“This [the government’s argument] prevents the use of circumstantial evidence envisioned by the preponderance standard and negates the system created by Congress, in which close calls regarding causation are resolved in favor of injured claimants. … While this case involves the possible link between TT [tetanus toxoid] vaccination and central nervous system injury, a sequence hitherto unproven in medicine, the purpose of the Vaccine Act’s preponderance standard is to allow the finding of causation in a field bereft of complete and direct proof of how vaccines affect the human body.”
Althen, 418 F.3d at 1280.