Under Daubert, what’s the persuasive value of one case report in a scientific jounal or one investigator’s assessment that an adverse event in a clinical trial was “definitely” related to taking the drug?

Essentially nothing, right?

One stray assessment is not statistically significant. It has not been reproduced. It has no known error rate. In the world of science, a case report may be an interesting anecdote, but’s it’s proof of nothing. And, under Daubert, that one report would not be sufficient scientific proof even to get a case to a jury.

Next question: Under Daubert, what’s the persuasive value of one jury verdict that a drug caused a plaintiff’s injury?

Essentially nothing, right?

That jury verdict suffers from all of the flaws of a case report. It’s not statistically significant, reproducible, or proof of anything. Indeed, it’s probably less persuasive than a case report or a relatedness assessment, because a jury verdict is not even a scientist’s best judgment; it is only the best judgment of a jury of twelve (or fewer) lay people.

Last question: Under Parklane Hosiery and the doctrine of non-mutual offensive collateral estoppel, what’s the persuasive value of one jury verdict that a drug caused a plaintiff’s injury?

Plaintiffs’ lawyers would tell you that it’s the whole ball game — past, present, and future. Counsel would (and do) assert that a single jury’s determination that a drug caused one plaintiff’s injury resolves an issue that was in dispute — general causation — in a context in which the issue should have been fully and fairly litigated. Counsel thus assert that the doctrine of collateral estoppel means the issue of general causation is forever decided adversely to the drug company; the drug company should be barred from re-litigating the general causation issue in any other case.

Happily, Parklane Hosiery itself provides many escapes from this absurd result, including the unfairness that it would create. Although we haven’t researched this issue recently, our sense is that courts rarely find that a single plaintiff’s verdict in a product liability case (or in the first of a series of cases) conclusively reolves the general causation issue as a matter of law.

But isn’t Daubert another reason for judges to laugh plaintiff’s counsel out of the courtroom when they press this position? If a single case report or relatedness assessment by a scientist would be considered unscientific evidence and unpersuasive proof of general causation under Daubert, shouldn’t a single jury verdict be entitled to even less respect? And, if so, isn’t it crazy — and inconsistent with the Supreme Court’s intentions when it decided Daubert — to suggest that one jury verdict somehow conclusively resolves the scientific issue of general causation?

If we’re right, we’d sure like to se defense counsel start raising that point, and we’d hope to see it begin to appear in the case law.