Opinion ID: 1919140
Heading Depth: 1
Heading Rank: 26

Heading: Ruling Out Potential Sources of Error

Text: Likewise, disagreements exist among courts regarding the importance of statistical significance. Some courts have required the relative risk in epidemiological studies to be statistically significant. [143] And the U.S. Supreme Court affirmed a district court's exclusion of an expert's opinion, in part, because one supporting study failed to find an association between the agent and the disease and another study failed to show that the increased risk of the disease was statistically significant. [144] [22] We agree that statistical significance is the most obvious way for a court to determine that researchers properly ruled out random variations in the population sample accounting for the result. But those decisions requiring a study's relative risk to be statistically significant have come under fire. Experts have pointed out that the lack of statistical significance does not demonstrate that there is no relationship. [145] So not all courts impose a requirement of statistical significance. [146] We also decline to impose a statistical significance requirement if an expert shows that others in the field would nonetheless rely on the study to support a causation opinion and that the probability of chance causing the study's results is low. [23] We also recognize that bias and uncontrolled confounding can present serious flaws in a study. But, as a practical matter, we do not expect trial courts to delve into every possible error in an expert's underlying data unless a party raises it: [W]here one party alleges that an expert's conclusions do not follow from a given data set, the responsibility ultimately falls on that challenging party to inform (via the record) those of us who are not experts on the subject with an understanding of precisely how and why the expert's conclusions fail to follow from the data set. [147] [24] Moreover, no study is without some errors of this nature and many prove inconsequential. [148] Thus, a court should normally not question a published epidemiological study's results over the mere possibility of error unless the study's findings plausibly appear attributable to unrecognized error. [149]