It isn’t unusual that phrases are used with out information of their origin and that the origin is instructive in regards to the which means or correct utility of the time period. We provide two examples. Many attorneys who at the very least dabble in product legal responsibility litigation have heard the time period “Bradford Hill standards.” Was it named after two totally different folks like Smoot and Hawley or Hatch and Waxman? Was it developed as a cheat sheet for attorneys and judges? No and no. Sir Austin Bradford Hill was already a well-known (and knighted) British statistician when he delivered the President’s Deal with upon the inaugural assembly of the Occupational Medication Part of the Royal Society for Medication in January 1965. On that august event, he posed two lawyerly questions, “In what circumstances can we move from this noticed affiliation to a verdict of causation? On what foundation ought to we achieve this?” He then proceeded to establish 9 components, components, or standards for the method of evaluating such questions of common causation. Therefore, the eponymous time period Bradford Hill standards. However observe that this was not about evaluating whether or not there was any affiliation between an publicity and an final result every drawn from the proverbial hat. As a substitute, an affiliation, usually established by means of observational analysis with statistically vital outcomes, was the place to begin. As SABH mentioned, “Our observations reveal an affiliation between two variables, completely clear-cut and past what we might care to attribute to the play of probability. What facets of that affiliation ought to we particularly think about earlier than deciding that the most probably interpretation of it’s causation?”
Our second instance is a “Daubert problem.” Youthful readers could have practiced with the Supreme Court docket’s Daubert choice as a long-established cornerstone of just about all litigation. But, we keep in mind when it got here out in 1993 and the way its contours had been nonetheless being formed for years to observe. Earlier than Daubert, the Frye normal had lengthy reigned in federal court docket and lots of states. Frye got here out of a racially charged homicide conviction the place the defendant’s exculpatory professional opinion based mostly on the outcomes of a lie detector check had been excluded. The affirmance by the D.C. Circuit set the brand new check, requiring that “the factor from which the deduction is made have to be sufficiently established to have gained common acceptance within the specific subject wherein it belongs.” Whereas Frye was seen as a excessive bar initially, by the Eighties, a cadre of practitioners of the traditional artwork of junk science had been routinely permitted to supply medical causation opinions at trial regardless of common causation being something however typically accepted. They, and the attorneys who employed them, knew methods to wrap their opinions within the cloak of common acceptance by saying their deductions on causation had been drawn based mostly on the appliance of “issues” just like the Bradford Hill standards, Koch’s postulates, and differential prognosis. Listening to the thrill phrases, many judges admitted the novel causation opinions, leaving the debunking of the junk as much as cross-examination. One massive litigation over a now-exonerated remedy associated to delivery defects allegedly attributable to maternal use of Bendectin. Daubert got here out of this context and the absence within the then-applicable model of Fed. R. Evid. 702 of any point out of “common acceptance” or “reliability.” In 2000, after Daubert had already spawned many notable progeny, Fed. R. Evid. 702 and 703 had been amended to replicate one thing of the truth from the caselaw. Thirty years later—an excellent 100 years after Frye—Fed. R. Evid. 702 has been revised once more, largely to remind judges that the “gatekeeping” accountability articulated in Daubert can be a factor. A Daubert problem is mostly a Rule 702 problem now.
We begin with that diatribe not just because we have a tendency to incorporate a little bit of blather earlier than diving into the choice we’re discussing, however as a result of the exclusion of plaintiffs’ common causation consultants in an obvious MDL-ending Rule 702 choice in In re Acetaminophen ASD-ADHD Prods. Liab. Litig., — F. Supp. 3d _-, 2023 WL 8711617 (S.D.N.Y. Dec. 18, 2023), is a worthy inheritor to the historical past above. For one factor, it pertains to alleged opposed results on the offspring of girls who used a sure remedy whereas pregnant. For an additional, the drug at subject has been used very extensively for a lot of many years and it’s on the World Well being Group’s Checklist of Important Medicines. The drug and the circumstances at subject within the litigation, autism spectrum dysfunction (ASD) and a spotlight deficit hyperactivity dysfunction (ADHD) have been extensively studied. A causal relationship isn’t accepted and, earlier than the litigation, a mere affiliation most likely was not accepted. But, there have been a whole lot of instances, hundreds of thousands spent on promoting, and an MDL established. As well as, though we typically don’t converse of judges, we observe that the choose overseeing this MDL took the federal bench in 1994—a yr after Daubert—and had a, let’s say, fascinating historical past with problems with preemption and the FDA over the primary yr or so of the MDL. This choice can be the primary MDL-wide choice of this scope making use of the brand new model of Rule 702. And, in case the foreshadowing was inadequate, the court docket’s gatekeeping perform, usually using the Bradford Hill standards, was on full show.
The info and posture are pretty easy. After rejecting preemption on the movement to dismiss stage, the court docket solicited and FDA refused to offer its enter on the plaintiffs’ purportedly sufficient warning as to the danger of ASD and ADHD with a spread of acetaminophen-containing OTC merchandise. The events then proceeded to professional discovery on common causation, which is a wise factor to do in an MDL like this if it will get that far and plaintiffs don’t get do-overs once they lose (see right here and right here). The plaintiffs right here put collectively a robust slate of consultants, at the very least based mostly on credentials, with an epidemiologist who will probably be taking on as Dean of the Harvard College of Public Well being as their lead. 2023 WL 8711617, *2. According to the Acetaminophen choice itself, we’ll deal with the problem to his common causation opinion, which plaintiffs tried to buttress with material consultants attempting to handle points like mechanism and organic plausibility. We is not going to go into all of the ins-and-outs of the science mentioned, however the court docket began with some fundamentals. That included that utilization of acetaminophen by pregnant ladies is quite common, each ASD and ADHD are pretty prevalent in U.S. kids, and the overwhelming majority of instances of ASD and ADHD are thought of to resulting from heritable genetics. Id. at *4. Mixed with no recognized genes or organic pathways for these circumstances, and comparatively few acknowledged threat components for them, these info make it extremely unlikely that an previous, widely-used drug would trigger both of those circumstances, not to mention each.
The court docket subsequent laid out the ideas for deciphering causation from epidemiologic and animal research. This recitation relied closely on the Reference Guide on Scientific Proof (3d ed. 2011), which could have been our third instance above. Again once we began writing Daubert motions, the RMSE (as Acetaminophen calls it) was required studying. The primary version was printed by the Federal Judicial Heart months after Daubert was determined and it mirrored a collaboration of distinguished scientists, judges, and attorneys. The identical is true for the 2 revisions since. Citing the RSME, the court docket acknowledged, “It is very important observe that epidemiology can not show causation; fairly, causation is a judgment to be made by epidemiologists and others deciphering the epidemiologic information.” Id. at *7. Thus, the important thing query in Acetaminophen was “whether or not it’s dependable to attract a causal inference from the associations that researchers have noticed between prenatal acetaminophen publicity, ASD, and ADHD.” Id. This formulation displays an understanding of what we famous above in regards to the Bradford Hill standards: There will be no correct causation evaluation with out predicate proof from human research, however a easy affiliation reported in research doesn’t supplant the necessity for an evaluation. The court docket then proceeded to evaluation the printed research. Boiled down, the overwhelming majority of analyses in printed research didn’t discover any elevated threat of ASD or ADHD and people who did discovered modest will increase, typically based mostly on some mixture of poor publicity ascertainment, inappropriate lumping of endpoints, and questionable subgroup analyses. (If we had been to focus on an space the place the court docket didn’t go far sufficient, then we would level out the necessity to establish when analyses weren’t predetermined appears to be like at major endpoints. In a paraphrase of the testimony of a tough opposing epidemiology professional who handed away just lately, “you need to say what you’ll do after which do what you say.” Now we have a robust suspicion that a lot of the elevated threat calculations the plaintiffs’ consultants appreciated had been the results of submit hoc slicing, dicing, and reassembling of the info (e.g., together with all neurodevelopmental points to get an elevated threat in a research that was solely designed to take a look at ASD).)
The following step was to establish the absence of any regulatory or skilled physique of observe endorsing a causal relationship between acetaminophen use and ASD or ADHD. This included the FDA, which didn’t weigh in on plaintiffs’ proposed labeling however just lately confirmed its view that “the restrictions and inconsistent findings of present observational research of APA and neurobehavioral and urogenital outcomes are unable to assist a willpower of causality.” Id. at *13. That FDA doesn’t imagine a real affiliation requiring a warning exists can be apparent. But, three of plaintiff’s consultants presupposed to have utilized the Bradford Hill standards to come back to the alternative conclusion. “At no level have plaintiffs instructed that their consultants might have glad their burden to supply dependable testimony of common causation with out performing a dependable Bradford Hill evaluation.” Id. at *22. This, together with the court docket’s emphasis on the proponent’s burden and the court docket’s gatekeeping perform per the revision of Rule 702 (see id. at n.27), set the stage for the core evaluation and this conclusion:
As defined infra, nonetheless, they haven’t used that literature to render discrete opinions relating to that publicity and the danger of ASD and the danger of ADHD. As a substitute, they’ve utilized a “transdiagnostic” evaluation that sweeps into their analyses (and conclusions) ASD, ADHD and different neurodevelopmental issues. They’ve failed to point out that their methodology in doing so is usually accepted by the scientific neighborhood. In any occasion, right here, their analyses haven’t served to enlighten however to obfuscate the weak point of the proof on which they purport to rely and the contradictions within the analysis. As carried out by the plaintiffs’ consultants, their transdiagnostic evaluation has obscured as an alternative of informing the inquiry on causation.
Id. at *16. For individuals who learn many Daubert choices, there may be fairly a bit packed into the above quote. Essentially, it displays a rejection of the concept that a well-qualified professional can supply a novel common causation opinion simply by citing some research findings and mouthing the magic phrases “Bradford Hill standards.” As a substitute, the proponent of the professional proof has to show that every step of the professional’s evaluation mirrored a “dependable utility of [reliable] ideas and strategies to the info of the case.” Fed. R. Evid. 702(c)-(d).
The court docket walked by means of the opinions and the appliance of ideas and strategies to kind them for every of plaintiffs’ 5 consultants. As for the plaintiff’s epidemiologist, Dr. Baccarelli, he was not solely effectively certified however he had co-authored three research on maternal acetaminophen use and varied neurodevelopmental outcomes. This tied to one in all his failings—shared by the opposite plaintiffs’ consultants—in attempting to depend on research information associated to outcomes aside from ASD or ADHD to fill within the gaps for the dearth of research information supporting a relationship with ASD and ADHD. The plaintiffs referred to as this a “transdiagnostic analysis,” a gloss on the inappropriate lumping we mentioned above. The court docket used plaintiffs’ time period, however clearly noticed the sport being performed. “In any case, this litigation is dropped at receive restoration on behalf of those that have been recognized with ASD or ADHD, not on behalf of anybody with, for instance, a deficit in communication or self-regulation.” Id. at *20. But Dr. Baccarelli by no means performed separate and distinct analyses for ASD and ADHD. Dr. Baccarelli additionally cherry-picked when he would depend on a special endpoint, as his “evaluation of a research’s use of non-ADHD, non-ASD endpoint appears to rely upon whether or not the research’s outcome helps his final opinion a few causal reference to prenatal publicity to acetaminophen.” Id. at *21. Thus, his “use of a transdiagnostic Bradford Hill evaluation fail[ed] to satisfy the necessities for admissibility on the difficulty of causation for ASD or ADHD.” Id. at *23.
Nonetheless, the court docket proceeded to take a look at every of the 9 standards and the way Dr. Baccarelli claimed to have utilized them. The court docket discovered that he failed, or, fairly, plaintiffs failed to point out he reliably utilized, seven of the 9 standards. A few of this will likely have been affected by the cussed refusal to confess that greater than one of many standards weighed towards causation, as consistency was clearly not met when most analyses in most research discovered no elevated threat and the energy of affiliation was clearly fairly low the place all however one research discovered no statistically elevated threat or an elevated threat beneath 2.0. Id. at *23-29. He conceded that specificity was not met, however claimed temporality was met as a result of by definition a baby’s prognosis of ASD or ADHD happens after the maternal publicity (if any) whereas pregnant with the kid. The court docket rightly noticed this as sophistry, specializing in the absence of proof or evaluation that put the publicity in research earlier than the event of ASD or ADHD throughout being pregnant. Id. at *29. Baccarelli’s opinion on dose-response (or “organic gradient” per Bradford Hill or “biologic gradient” per Baccarelli) relied largely on one other plaintiffs’ professional, whose opinion was itself excluded as unreliable, and in any other case“skate[d] over the complexities and limitations of the underlying literature.” Id. at *30. Baccarelli additionally tried to depend on the unreliable opinions of different plaintiffs’ consultants in concluding that the organic plausibility (simply “plausibility” per Bradford Hill) criterion was met. However “[s]cientists have at finest developed hypotheses” about mechanisms for the event of both ASD or ADHD in utero. Id. Many courts have let the flexibility to articulate some speculation, regardless of how unfounded, as satisfying this criterion, however Acetaminophen didn’t.
Plaintiffs carried their burden to point out that Dr. Baccarelli’s coherence evaluation was dependable. We are going to depart it at that, besides to say pairing speculative mechanisms proposed for circumstances with no recognized organic mechanisms doesn’t sound very coherent. Dr. Baccarelli claimed that the analogy criterion was met as a result of maternal use of a selected prescription drug has been related to “opposed results on neurodevelopment” per its label, however he couldn’t clarify why that was instructive about acetaminophen and ASD or ADHD. Id. at *31. The experiment criterion was largely punted given obvious settlement that human experimentation could be unethical and “the animal research can not bear the total weight of offering admissible proof of causation on this case.” Id. (The 2 plaintiff consultants who provided opinions based mostly on cherry selecting allegedly supportive animal research outcomes and ignoring opposite research had been additionally excluded.)
The evaluation of the opposite 4 plaintiffs’ consultants is price a learn, however Dr. Baccarelli’s destiny was clearly determinative of the admissibility of any common causation opinion. We wrap up with the court docket’s recitation of the justifications, er, arguments, provided by plaintiffs, all of which sought a decrease bar for admissibility of a novel causation opinion:
At oral argument, the plaintiffs requested the Court docket to deal with the truth that Dr. Baccarelli is a preeminent epidemiologist, which he’s. They ask that the Court docket ignore his printed statements acknowledging the weak point within the literature, arguing that he has been right to vary his thoughts when rendering his opinion right here. They stress the path of the affiliation proof, ignoring these research discovering no affiliation or a detrimental affiliation. They argue that it’s pointless to insist {that a} discovering of affiliation be statistically vital, arguing {that a} extra versatile normal ought to be adopted. They contend that the restrictions expressed by authors of their research ought to be ignored as merely a very conservative requirement that scientists impose on one another to get peer reviewed research printed. They recommend that the FDA’s surveillance of this subject since 2014 means little because the FDA was not vigilant in reviewing the dangers related to sure different medication and that it has not carried out a Bradford Hill evaluation. These and extra arguments like them don’t relieve the Court docket of the duty to scrutinize the methodology utilized by Dr. Baccarelli to make sure that it’s sufficiently rigorous to move muster by the requirements established by his self-discipline, Rule 702 and Daubert.
Id. at *35. To us, this reads like a abstract of what plaintiffs usually say about unfavorable science at trial. The one factor lacking was accusing the defendants of shopping for the science. It additionally reminds us of the oft quoted scene from A Few Good Males the place an legal professional follows up on an overruled objection to excluding an professional opinion with a “strenuous” objection to the identical opinion. The distinction with Acetaminophen is that the plaintiff attorneys who created the litigation ought to have recognized from the beginning that that they had very weak common causation proof. Maybe they anticipated the defendants to settle earlier than that weak point was examined. Whereas this litigation additionally would have been a great candidate for an early decisive preemption ruling in favor of the producers, the court docket’s ruling rejecting what was clearly plaintiffs’ finest shot ought to be equally decisive.
