Plaintiffs claim that a causal connection exists between Accutane, a prescription drug used in the treatment of nodular acne, and Crohn's disease, a chronic gastrointestinal illness. Litigation in New Jersey over Accutane's side effects has spanned more than a decade. This action is a continuation in that series of litigated matters. Since those actions first commenced in New Jersey in 2005, a number of epidemiological studies have been published, all concluding that there is no causal relationship between Accutane and Crohn's disease. Plaintiffs' experts dispute the conclusions of those studies, calling them flawed and lacking in value. Having rejected the evidence and conclusions of those epidemiological studies, one of plaintiffs' experts, relying on other facts and forms of data, asserts the contrary view that Accutane can in fact cause Crohn's disease. Defendants challenged the methodology used by both of plaintiffs' experts as unreliable and sought the exclusion of that expert testimony.
After a Rule 104 pretrial evidentiary hearing, the trial court excluded the testimony, holding that plaintiffs' experts' methodology was unsound because they did not interpret the relevant data and apply it to the facts of this case as would
We granted certification in this matter to address whether the trial court properly excluded plaintiffs' experts' testimony, whether the Appellate Division employed the correct standard in reviewing and overturning that decision, and whether our standard for assessing the reliability of expert witnesses is in need of clarification. It is with regard to the last issue that we are asked whether the Daubert standard's factors would further elucidate our own standard for the admissibility of expert testimony. We believe that they would.
We perceive little distinction between Daubert's principles regarding expert testimony and our own, and believe that its factors for assessing the reliability of expert testimony will aid our trial
This case -- with its adversarial setting and full record -- provides the appropriate setting for illustrating how courts should evaluate the methodology of a credentialed expert when determining whether an opinion is based on scientifically sound reasoning. See Kemp ex rel. Wright v. State,
I.
Before diving into the record and its contested scientific evidence, we set forth
New Jersey Rules of Evidence 702 and 703 control the admission of expert testimony. N.J.R.E. 702 provides that "[i]f scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify thereto in the form of an opinion or otherwise." N.J.R.E. 703 states that
[t]he facts or data in the particular case upon which an expert bases an opinion or inference may be those perceived by or made known to the expert at or before the hearing. If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence.
(1) the intended testimony must concern a subject matter that is beyond the ken of the average juror; (2) the field testified to must be at a state of the art such that an expert's testimony could be sufficiently reliable; and (3) the witness must have sufficient expertise to offer the intended testimony.
[, 223, 97 N.J. 178 (1984).] 478 A.2d 364
That standard provides the baseline for the admissibility of expert testimony. See Official Comments to N.J.R.E. 702 (noting that N.J.R.E. 702 incorporates standard articulated by Kelly ).
The Kelly criteria elucidated application of the then-applicable "general acceptance" standard for admitting scientific evidence, which originated in Frye v. United States,
This Court held in Rubanick that a court may admit expert scientific evidence on a causation theory in toxic tort litigation so long as "it is based on a sound, adequately-founded scientific methodology involving data and information of the type reasonably
A Kemp hearing provides the record for the present matter. After the conclusion of that hearing, the trial court determined that the contested evidence did not pass muster under our Rubanick evidentiary standard for assessing the reliability of proffered expert scientific testimony. The court made its findings in response to argument by the parties, rejecting the soundness of plaintiffs' experts' methodology.
II.
A.
Accutane is a prescription medication developed by defendants Hoffman-La Roche Inc. and Roche Laboratories Inc. (defendants) and approved by the FDA in 1982 to treat recalcitrant nodular acne. Known chemically as isotretinoin, Accutane is part of a family of Vitamin A derivatives called retinoids. During the pre-approval clinical studies of Accutane, roughly a fifth of patients suffered some form of gastrointestinal side effects. Defendants also learned, after Accutane was on the market, that users were suffering symptoms of gastrointestinal upset such as inflammatory bowel disease (IBD) and peptic ulceration. Defendants eventually
Accutane's alleged role as a cause of gastrointestinal disease ultimately resulted in a series of lawsuits against defendants. On May 2, 2005, this Court designated all pending and future New Jersey actions involving Accutane as a mass tort Multicounty Litigation (MCL) pursuant to Rule 4:38A. All cases involving Accutane were subsequently transferred to Atlantic County to be heard on a coordinated basis.
The present matter, the latest in a series of cases,
In the years since many of the earlier cases regarding Accutane and IBD were decided, a series of epidemiological studies were published regarding the potential connection between Accutane and IBD, all of which concluded that Accutane is not causally associated with the development of Crohn's disease. On September 23, 2014, defendants filed a motion seeking a Kemp hearing on the association between Accutane and Crohn's disease. Defendants argued that epidemiological studies published in the scientific
The trial court scheduled a Kemp hearing to begin on February 2, 2015.
B.
The testimony focused intently on the aforementioned epidemiological studies. Accordingly, some background on the use of such studies in the formation of causal analyses provides context for the discussion of the evidence by the parties and the trial court. Much of the following discussion is taken from the Federal Judicial Center's Reference Manual on Scientific Evidence (3d ed. 2011), a source frequently relied on in the trial court proceedings.
Epidemiology "studies the incidence, distribution, and etiology of disease in human populations."
Epidemiological studies are used to test whether exposure to a particular agent causes a harmful effect or disease.
Among the different kinds of epidemiological studies, randomized trials are "considered the gold standard for determining the relationship of an agent to a health outcome or adverse side effect."
1. Do the results of an epidemiologic study or studies reveal an association between an agent and disease?
2. Could this association have resulted from limitations of the study (bias, confounding, or sampling error), and, if so, from which?
3. Based on the analysis of limitations in Item 2, above, and on other evidence, how plausible is a causal interpretation of the association?
[Id. at 554.]
Once an association has been found between exposure to a particular agent and development of a specific disease, researchers then consider whether that association "reflects a true cause-effect relationship." Id. at 597. To do so, researchers look to alternative explanations, such as bias or confounding factors, and then consider how well-recognized "guidelines for inferring causation from an association apply to the available evidence." Id. at 598. However, and importantly, those accepted "guidelines are employed only after a study finds an association to determine whether that association reflects a true causal relationship." Id. at 598-99. Commonly referred to as the "Hill criteria" or "Hill factors,"
1. Temporal relationship,
2. Strength of the association,
3. Dose-response relationship,
4. Replication of the findings,
5. Biological plausibility (coherence with existing knowledge),
6. Consideration of alternative explanations,
7. Cessation of exposure,
8. Specificity of the association, and
9. Consistency with other knowledge.
[Id. at 600.]
Finally, in addition to observational epidemiology, researchers sometimes look to animal studies for determining a given
Beginning in 2009, scientists began examining the issue of Accutane's causal relationship to Crohn's disease through the lens of epidemiological studies. The first of those studies, published by Bernstein et al.
C.
Plaintiffs and defendants each produced two expert witnesses. Plaintiffs produced Dr. Arthur Asher Kornbluth, a gastroenterologist, and Dr. David Madigan, a statistician. Defendants produced gastroenterologist Dr. Maria Oliva-Hemker, and biostatistician Dr. Steven Goodman.
1. Plaintiffs' Expert -- Dr. Kornbluth
Plaintiffs' expert Dr. Arthur Asher Kornbluth is a board-certified physician in internal medicine and in the subspecialty of gastroenterology. He maintains an active clinical practice treating Crohn's disease and ulcerative colitis and is also a Clinical Professor of Medicine at the Icahn School of Medicine at Mount Sinai Hospital in New York City.
Dr. Kornbluth's testimony had two themes: explaining why he found the epidemiological studies unreliable and uninformative regarding the issue of causation, and explaining his reliance on other forms of evidence such as case reports, animal studies, causality assessments, and his biological mechanism hypothesis.
With regard to the epidemiological studies, Dr. Kornbluth explained that he would not rely on any study that did not provide separate data for Crohn's disease. As a result, he found the Fenerty and Rashtak studies -- both of which analyzed data for IBD generally and not for Crohn's disease specifically -- to be uninformative. As for the studies that did look specifically for Crohn's disease, Dr. Kornbluth stated that most of them, including the Alhusayen, Crockett, Etminan, and Racine studies, were fatally flawed because they did not account for Crohn's disease's"prodrome,"
Dr. Kornbluth detected other problems with the epidemiological studies. He asserted that the Crockett, Bernstein, and Etminan studies did not have enough patients and thus were "underpowered," meaning that they were not properly designed to detect a statistically significant increased risk, even if such a risk actually existed, because the study size was simply too small. He asserted that the Alhusayen and Etminan studies did not adjust for certain confounders, such as family history and smoking. With regard to the Racine and Bernstein studies, he noted that those studies were performed in France and Canada, respectively, and that French and Canadian patients typically receive half the Accutane dosage that American patients receive. Moreover, he noted that the protective effect found in the Racine study's results lessened as the dosages increased, indicating a dose toxicity response. He was also dismissive of the meta-analysis that the Etminan authors performed, stating that it suffered from the same limitations as the studies that went into it and that a meta-analysis based on studies that did not perform an "adequate analysis" could not inform the issue.
In the end, the Sivaraman study was the only study upon which Dr. Kornbluth was willing to rely. Even so, he disagreed with the study authors' conclusion. He explained that the study's unadjusted point estimate showed that "patients with Crohn's disease were five times more likely to have taken Accutane than those who did not," and that the study's unadjusted results also showed a statistically significant increased risk. However, in explaining why he disagreed with the Sivaraman authors' conclusion that Accutane does not cause Crohn's disease, he noted that the Sivaraman authors reached their adjusted point estimate by subtracting out patients who had taken antibiotics; while that adjusted point estimate still showed a heightened risk, the smaller number of patients meant that the result lost statistical significance. Moreover,
Moving beyond the epidemiological studies, Dr. Kornbluth examined other lines of evidence that he found supported his causation opinion. He began by explaining why he believes it is biologically plausible for Accutane to cause Crohn's disease, although he had not published his causation theory or otherwise submitted it for peer review.
He discussed his reliance on MedWatch reports -- "reports made by physicians, patients, [and] others to the FDA describing symptoms that they think were related to ingested medications." He noted the significant number of such reports relating to Crohn's disease and other gastrointestinal problems that correlated with the use of Accutane. Similarly, he testified that he relied on defendants' own internal materials, noting that defendants' scientists determined that Accutane should be contraindicated for individuals with certain gastrointestinal problems and expressed "severe concerns about the likelihood of patients having exacerbations
Finally, Dr. Kornbluth relied on animal studies to support his theory of causation. He testified that defendants performed experimental tests with Accutane on dogs
2. Plaintiffs' Expert -- Dr. Madigan
Plaintiffs' second expert, Dr. David Madigan, is a professor of statistics at Columbia University. Dr. Madigan did not give a causation opinion. Only Dr. Kornbluth opined on causation.
Dr. Madigan's testimony and expert report focused solely on whether the epidemiological studies in question were appropriately designed to discover an association between Crohn's disease and Accutane, if such an association did in fact exist. He concluded in his expert report that, after accounting for the prodrome associated with Crohn's disease, the available epidemiological studies do not provide statistically reliable information regarding Accutane's causal relation to Crohn's disease. His testimony was consistent with his report.
Dr. Madigan explained that he was tasked with examining the available epidemiological studies as they pertained to an association between Accutane and Crohn's disease. He analyzed six of the epidemiological studies: Bernstein, Crockett, Alhusayen, Etminan, Racine, and Sivaraman. He did not analyze the Rashtak and
Dr. Madigan noted that of the six studies he considered, only two -- Racine and the unadjusted Sivaraman results -- were statistically significant. Dr. Madigan performed a "power analysis"
Dr. Madigan then examined each study's statistical power to detect a fifty percent increased risk; he chose fifty percent because he considered it to be "an authentically important increased risk." He calculated the power for each of the four studies as follows: Bernstein -- 37.8 percent; Crockett -- 18.2 percent; Alhusayen -- 89.4 percent; Etminan -- 22.6 percent. Thus, for example, if there is a fifty percent increased risk of developing Crohn's disease for Accutane users, the probability that the Bernstein study would find a statistically significant result is 37.8 percent. It was thus "less likely than not" that most of the studies would find an increased risk if such a risk did in fact exist. Dr. Madigan concluded that this was "more an absence of evidence than anything." After accounting for the median prodromal period, which he derived from the Pimentel and Barratt studies, he determined that the power for three of the four studies had further decreased: Crockett diminished to
According to Dr. Madigan, four of the six studies -- Crockett, Alhusayen, Etminan, and Racine -- were totally unusable because they failed to account for Crohn's disease's prodrome. He explained that by failing to account for the prodrome, the studies were failing to observe cases of Crohn's disease that developed
As for the remaining two studies, he explained that questionnaire-based studies such as Sivaraman are immune from the prodrome issue because they ask patients when their symptoms began and, thus, have "no limit going backwards in time." He also explained that there was a "diminished concern" for the Bernstein study due to its lengthy observation period. However, Dr. Madigan found other flaws in the Bernstein study, and he declined to rely on its findings. He stated that the study did not adjust for "unmeasured confounders" and it was performed in Canada rather than the United States, which created a problem as to "generalizability" due to differences in population and the lower dosage given to Canadian patients.
Accordingly, for Dr. Madigan, the Sivaraman study remained as the only study on which he was willing to rely, but with caveats. He did not agree with its conclusion. He pointed to the study's unadjusted results as showing a statistically significant increased risk of Crohn's disease for people taking Accutane. Although he acknowledged that the study's authors felt it necessary to adjust for antibiotic exposure, and that their adjusted results did not show a statistically significant increased risk for Crohn's disease, Dr. Madigan disputed that they actually performed an adjustment. He claimed that they actually performed a "subgroup analysis." He asserted that the adjusted figure from that analysis still showed an increased risk, even though it was no longer statistically significant due to the smaller number of patients. Accordingly, he chose to rely on the unadjusted results because a study based on a larger group of people will provide a "better estimate." He further explained that he did not understand why the study authors chose to adjust for antibiotic exposure because the study
In sum, Dr. Madigan found the Sivaraman study to be "evidence of a strong association between Accutane and Crohn's disease," discounting all of the other studies on the basis that they "represented an absence of evidence" from which one cannot draw any definitive conclusions.
Dr. Madigan also took the position that a meta-analysis of the studies would be improper. He stated he did not perform a meta-analysis because most of the studies on which the meta-analysis would be based did not account for prodrome, which would render the meta-analysis both misleading and scientifically unreasonable. That is so, he explained, because a meta-analysis will inherit the flaws, biases, and structural problems of the studies upon which it is based.
In addition, Dr. Madigan performed a disproportionality analysis using the FDA's spontaneous reporting system database. He explained that a disproportionality analysis is a method of studying a spontaneous
3. Defendants' Expert -- Dr. Oliva-Hemker
Defendants' expert Dr. Maria Oliva-Hemker is a Professor of Pediatric Inflammatory Bowel Disease and Chief of the Division of Pediatric Gastroenterology and Nutrition at Johns Hopkins University School of Medicine. Her testimony focused on disputing Dr. Kornbluth's testimony and explaining why epidemiological studies are preferred to case reports and animal studies in the hierarchy of evidence.
She also addressed plaintiffs' experts' opinions concerning the prodrome for Crohn's disease. Although admitting that "the diagnosis time can vary" and that there are some patients who are not diagnosed for several years, she stated that most patients are typically diagnosed within a year. She based that conclusion on a number of population-based studies, all of which concluded that the median prodrome is under one year. She was dismissive of plaintiffs' experts' use of the Pimentel study for determining the median prodrome for Crohn's disease, explaining that the study was very small and not representative of the average prodromal period, especially in light of the other, larger studies on the issue. She added that the authors of the epidemiological studies would have been aware of the available published data on the median prodromal period and would have accounted for it in designing their studies.
She also discussed the recognized hierarchy of evidence and that certain types of data are meant to "generate hypotheses," whereas other, more reliable forms of evidence are meant to "test hypotheses." She stated that the epidemiological studies are currently the best available data on the issue of Accutane and Crohn's disease and that, from a medical-evidence point of view, Dr. Kornbluth's reliance on case reports and animal studies, which are considered lower forms of evidence, was inconsistent with recognized methodology. Concerning case reports, she testified that they are hypothesis-generating in nature and are "in the bottom tier of medical evidence." She explained that case reports are
Finally, Dr. Oliva-Hemker addressed Dr. Kornbluth's interpretation of defendants' animal studies. She stated that animal studies may sometimes be important for "generating certain hypotheses," but that they are typically considered below human studies in the hierarchy of medical evidence. She noted that it is difficult to extrapolate data from animals to humans because of differences in metabolism, absorption, and other factors. Moreover, she testified that she would not rely on dog studies in this instance because dogs cannot get IBD and because recent research has shown that dogs may have hypersensitive gastrointestinal tracts that can result in distress owing more to the dog's anatomy than to the actual toxicity of the substance under observation. In sum, her testimony concluded that the animal studies are simply not sufficient generally for forming a conclusion about causation here both because of the nature of the disease at issue and because they are merely "hypothesis-generating data."
In contrast to the case reports and animal studies, she testified that the epidemiological studies are the best available evidence on the issue of Accutane's relation to Crohn's disease. Moreover, she testified that it would be entirely proper to consider a meta-analysis of the studies when such analysis is available. She explained that researchers now have access to the types of "hypothesis
4. Defendants' Expert -- Dr. Goodman
Defendants' second expert, Dr. Steven Goodman, is a Professor of Medicine and Health Research and Policy and Associate Dean for Clinical and Translational Research at Stanford University, where he serves as Chief of the Division of Epidemiology and co-director of Stanford's Meta-Research Innovation Center. Dr. Goodman's testimony focused on why the epidemiologic evidence is the best available evidence on the question of Accutane's causal relation to Crohn's disease and why a meta-analysis was a proper way of pooling those study results to reach a conclusion that Accutane does not cause Crohn's disease.
Dr. Goodman stated, during the Kemp hearing and in his expert report, that the epidemiological evidence pertaining to the causal relationship between Accutane and Crohn's disease is as strongly negative as epidemiologic evidence can be, and that there was no biological evidence, including a causal mechanism or otherwise, to contravene that evidence. He stated that the methods Doctors Madigan and Kornbluth used were flawed because they put almost no weight on the epidemiologic evidence and instead relied heavily on the much lesser forms of evidence, which is not how any scientific body would have proceeded. Dr. Goodman emphasized that there is now a consistent body of epidemiological evidence all pointing towards no causal association between Accutane and Crohn's disease and that the weighing of that body of evidence through use of meta-analysis also strongly supported the lack of any association or causal effect between Accutane and Crohn's disease.
Dr. Goodman discussed the hierarchy of medical evidence, stating that observational
For similar reasons, Dr. Goodman was also dismissive of Dr. Kornbluth's interpretation of animal studies, explaining that such studies are hypothesis-generating in nature and that it is difficult to extrapolate results from animal studies to determine the effect a given substance will have on a human subject. Moreover, he believed that the specific animal studies discussed in this matter were essentially meaningless because dogs do not develop IBD. He also took issue with Dr. Kornbluth's invocation of the Hill criteria in assessing the causal relationship between Accutane and Crohn's disease because the studies here showed no strength of association, and so there was no "association" in need of study.
After reviewing all of the epidemiologic evidence, Dr. Goodman stated that none of the studies showed a statistically significant increased risk of developing Crohn's disease from use of Accutane. In addition to his belief that each study contained reasonable results, he also noted the importance of the fact that all of the studies were concordant with each other -- that all of the studies produced consistent results pointing in the same direction was strong evidence that those results are reliable.
With regard to the Sivaraman study, he stated that the study should be interpreted according to its adjusted numbers, and that it was proper for the study authors to adjust for antibiotics. He explained that the adjusted number is always better because it tends to be less biased and therefore more reliable. Moreover, he
He also explained the methodology of the meta-analysis he performed, describing how smaller and more imprecise studies are given less weight whereas larger and more precise studies are given more weight. He further stated that a meta-analysis is a way to increase precision by pooling studies that address the same question. Moreover, meta-analysis is useful where there is a question about whether independent studies are large enough to detect an effect size. Accordingly, he criticized Dr. Madigan's refusal to perform a meta-analysis of the studies despite arguing that most of the studies were underpowered because meta-analysis was "in a sense invented" to address power concerns.
He then went through the results of his meta-analysis, which he performed for both IBD and Crohn's disease. For IBD, the meta-analysis resulted in a relative risk indicative of a protective effect, but with a statistically insignificant confidence interval. For Crohn's disease, the meta-analysis again returned a relative risk indicative of a protective effect, with a non-statistically significant confidence interval.
Finally, Dr. Goodman turned his attention to the criticisms levied against the epidemiological studies -- specifically the prodrome issue on which plaintiffs' experts chiefly relied in disregarding the studies. Dr. Goodman criticized plaintiffs' experts' reliance on the Pimentel and Barratt studies for determining a median prodrome length of at least two-to-four years because of the studies' small size and because the Pimentel study's population was taken from patients who gastroenterologists found difficult to manage and diagnose. Dr. Goodman felt that a study by Chouraki et al.,
D.
After the Kemp hearing, the trial court issued an order granting defendants' omnibus motion to bar plaintiffs' experts from testifying on, among other things, whether the epidemiological studies on which the defense relied were flawed and unreliable and whether Accutane can cause Crohn's disease. The trial court also directed the parties to prepare an order listing the lawsuits affected by the ruling, and subsequently issued a May 8, 2015 order dismissing 2076 affected claims with prejudice.
In its decision concerning the exclusion of plaintiffs' expert witnesses, the trial court examined the expert testimony and scientific studies, laid out the relevant standard for the admission of expert witness testimony, and determined that plaintiffs' experts' testimony did not meet the applicable standard.
The trial court stated that Rubanick governed the admissibility of expert witness testimony in toxic tort cases in New Jersey. The court regarded the Rubanick standard, which it understood to be more flexible in assessing medical causation expert testimony than the "general acceptance" test of Frye otherwise traditionally used in New Jersey courts, as requiring an expert opinion to be based on a "sound, adequately-founded scientific methodology involving data of the type reasonably relied on by experts in the scientific field." (citing Rubanick,
The trial court applied that standard and found plaintiffs' experts' testimony lacking.
The trial court viewed Dr. Kornbluth and Dr. Madigan as "self-validating expert[s]" who were unwilling to subject their ideas for evaluation in the scientific community, either through peer review submission or through the scrutiny of the process of publication in scientific literature. Specifically regarding Dr. Kornbluth, the trial court stated that he "want[ed] to have it both ways" by rejecting the best available evidence as flawed and yet relying on inferior forms of evidence. As for Dr. Madigan, the trial court viewed his refusal to perform a meta-analysis and to instead rely on the Sivaraman study for causation and the Pimentel and Barratt studies for median prodrome, to the exclusion of all other studies, as an attempt to explain away the body of evidence on causation and on the median prodromal period.
The trial court therefore determined that plaintiffs' experts' examination of the evidence was a "conclusion-driven" attempt to cherry-pick evidence supportive of their opinion while dismissing other, better forms of evidence that did not support their opinion. The trial court believed that such a "stratagem cannot bridge the analytical gaps inherent in Plaintiffs' hypothesis."
The panel found plaintiffs' experts to be "extremely well-qualified" and underscored that they "considered all of the relevant data and information, applied appropriate methodology in analyzing the epidemiological studies, and expressed valid reasons for rejecting the conclusions of some of the epidemiological studies and in accepting other studies as supportive of their opinion."
The panel further noted that, although a trial court's decision to admit or exclude evidence is subject to an abuse of discretion standard, a reviewing court owes "somewhat less deference to a trial court's determination[s]" regarding expert testimony.
We granted defendants' petition for certification.
HealthCare Institute of New Jersey, the New Jersey Business & Industry Association, Commerce and Industry Association of New Jersey, and New Jersey Chamber of Commerce (collectively "the Industry Associations"); Kenneth S. Broun, Daniel J. Capra, Joanne A. Epps, David L. Faigman, Laird Kirkpatrick, Michael M. Martin, Liesa Richter, and Stephen A. Saltzburg (collectively "the Academics"); the American Medical Association, Medical Society of New Jersey, American Academy of Dermatology, Society for Investigative Dermatology, American Acne and Rosacea Society, and Dermatological Society of New Jersey (collectively "the Medical Associations"); the Pharmaceutical Research and Manufacturers of America; the New Jersey Civil Justice Institute (NJCJI); and DRI - The Voice of the Defense Bar (DRI), filed briefs supportive of defendants.
The New Jersey Association for Justice (NJAJ); the Ironbound Community Corporation (ICC); and Allan Kanner, Esq. (Kanner), filed briefs supportive of plaintiffs.
III.
A.
Defendants argue that the Appellate Division's decision effectively nullifies the trial court's role as the gatekeeper of expert witness testimony and will "allow[ ] any credentialed expert to argue their way to a jury." They contend that the appellate panel did not address the methodological inconsistencies inherent in plaintiffs' experts' reasoning and adopted a restrictive interpretation of the trial court's role as the "gatekeeper" of expert witness testimony that is at odds with precedent from both New Jersey
The current lack of clarity, defendants posit, has resulted in "vastly different applications of gatekeeping," as illustrated by the opposing viewpoints of the trial court and Appellate Division in this matter. Moreover, defendants argue that, "[a]lthough the Court need not adopt the federal Daubert standard to find that the Appellate Division erred, this case illustrates the practical benefits of doing so." Defendants add that the extent to which New Jersey courts may look to Daubert for guidance is currently unclear; they urge this Court to clarify that issue here.
With respect to the proffered expert scientific testimony, defendants contend that the Appellate Division failed to apply methodological scrutiny, improperly applying a "relaxed" standard for admissibility despite the existence of "well-developed science." By doing so, the Appellate Division allowed plaintiffs' experts to employ a methodology whereby they argued away better and more reliable forms of evidence such as epidemiological studies to rely on lesser forms of evidence such as case reports and animal studies. Thus, they contend that the Appellate Division ignored "key guidelines from this and other courts
Specifically, defendants argue that the Appellate Division did not consider whether the experts used the data as it is used by scientists in the field, a requirement mandated by Rubanick; condoned the experts' failure to adhere to the hierarchy of evidence; and failed to look for any demonstration of scientific consensus for the experts' methods or views, such as peer-reviewed articles or treatises. And, they argue that the Appellate Division did not give appropriate deference to the trial court's
In sum, defendants argue that appellate error has resulted in the allowance of expert testimony that is contradictory, unreliable, and logically incoherent. Defendants emphasize that none of the epidemiological studies concluded that there was a connection between Accutane and Crohn's disease. Doctors Madigan and Kornbluth were thus forced to use an inconsistent methodology whereby they "concocted" a theory on Crohn's disease's prodrome and selectively applied that theory to evidence that did not support their viewpoints. They did the same for their theories on study power, applying it where necessary to refute the evidence, but then ignoring it for the studies upon which they relied. Defendants argue that the experts' "contradictory methodology" should not be allowed to be advanced before a jury.
B.
Plaintiffs argue that the Appellate Division appropriately employed Rubanick's relaxed admissibility standard in this matter and properly assessed the reliability of plaintiffs' experts' methodology. Plaintiffs cite to the Reference Manual for the proposition that "epidemiology alone cannot prove causation," and contend that defendants have falsely categorized the nature of the expert testimony due to their erroneous belief that the epidemiological studies alone should be considered to the exclusion of all other evidence. According to plaintiffs, epidemiological studies "are not the be all and end all of causation evidence," but rather "one component of multiple lines of evidence that inform the causation issue." Thus, by considering all of the evidence in addition to the epidemiology, plaintiffs argue their experts employed a methodology based on sound scientific principles accepted in the scientific community. They further argue that the Appellate Division correctly found that their experts did not ignore the epidemiology, but rather examined the data with proper consideration of the strengths and limitations of the design of each of the studies,
Furthermore, plaintiffs argue that the Reference Manual does not endorse a "strict application" of the hierarchy of evidence. In fact, the Reference Manual does not suggest that epidemiological studies are "beyond scientific criticism" or that "no countervailing evidence should be considered." Plaintiffs thus contend that their experts did not stray from any "core scientific principles," but simply considered all of the evidence in forming their opinions. Plaintiffs posit that their experts merely viewed the epidemiological studies differently than defendants' experts, and that doing so is not improper because the "implications of a study are open to debate."
Plaintiffs also dispute the "key guidelines" identified by defendants for examining expert testimony. Plaintiffs note that the law does not require that experts submit their opinions for peer review in order to be admissible. Plaintiffs also take issue
Plaintiffs also argue that the Appellate Division gave appropriate deference to the trial court, explaining that "less deference is owed to a trial court when the issue is the admissibility of expert proofs." They claim that the trial court failed to adhere to the principles expounded in Rubanick, which provided "well-founded support for the level of review that the Appellate Division employed." Thus, because the trial court substituted its judgment for that of the jury and improperly weighed the evidence, the Appellate
C.
Amici curiae Industry Associations, the Academics, and DRI argue that New Jersey's expert witness standard is in need of clarification and urge this Court to join the majority of other states by adopting the Daubert standard to ensure meaningful judicial gatekeeping and that only reliable and reliably applied expert testimony enters New Jersey's courts. Similarly, amici curiae NJCJI and the Medical Associations argue that the Appellate Division reached an incorrect decision even under existing New Jersey law, but maintain that adoption of the Daubert standard will provide helpful guidance and ensure meaningful and robust gatekeeping in New Jersey trial courts.
Specifically, the Industry Associations and the Academics maintain that although Daubert and the current standard are somewhat similar, Daubert provides "concrete guidelines" and a more fulsome analysis that ensures that the expert's methodology is reliable and applied in a way that "fits" the facts of a case. Both contend that plaintiffs' experts' testimony would not have withstood that more thorough analysis. Moreover, both argue that tying New Jersey closer to the Daubert standard would discourage forum shopping. Finally, the Academics assert that the Appellate Division should have applied a pure abuse of discretion standard in reviewing the trial court's ruling.
The Medical Associations argue that the Appellate Division incorrectly applied New Jersey's expert witness standard by ignoring the hierarchy of evidence and the unanimity of epidemiological evidence in favor of plaintiffs' experts' "un-vetted postulations." They point to a scientific consensus in the medical literature that Accutane does not cause Crohn's disease, and argue that
NJCJI similarly argues that the Appellate Division permitted plaintiffs' experts to present their unsubstantiated "outlier viewpoint" without any meaningful judicial scrutiny or investigation of their methodology. NJCJI claims that the Appellate Division's decision improperly left the question
NJCJI and DRI emphasize that robust gatekeeping is necessary because juries struggle to absorb complex scientific concepts and are poorly equipped to assess methodological soundness. Both amici express the concern that juries may be misled by highly-qualified experts who offer opinions that are not supported by the wider scientific community and that juries faced with complex scientific evidence may simply "fall back" on an expert's credentials as a basis for evaluating the testimony at issue. To guard against that risk, DRI argues that experts should be required to prove not only that their methodology is sound, but that such methodology is reliably applied to the facts of the case.
Finally, amicus curiae Pharmaceutical Research and Manufacturers of America submitted a brief detailing the scientific principles at issue here and arguing that the trial court correctly excluded plaintiffs' experts' testimony.
D.
Amici curiae NJAJ, ICC, and Kanner argue that this Court should not adopt the Daubert standard because the current New Jersey standard is well-settled and strikes an appropriate balance between proper judicial gatekeeping and the admission of novel scientific concepts. NJAJ claims that the Daubert standard is a "patchwork" of case law that has been applied inconsistently by both state and federal courts. NJAJ and Kanner further contend
The NJAJ further argues that New Jersey's expert witness standard does not require any clarification or correction and that state trial courts have reliably applied it for many decades. NJAJ contends that defendants have provided no substantive reason why this Court should abandon the expert witness standards that it pioneered and "which continue to fairly promote just results." Furthermore, NJAJ disputes that New Jersey's current expert witness standard promotes the filing of cases in New Jersey by out-of-state plaintiffs, arguing that there is no evidence to support such an assertion. Finally, NJAJ, ICC, and Kanner maintain that the Appellate Division here applied the proper standard and properly found that the trial court exceeded its gatekeeping role by excluding plaintiffs' experts based on nothing more than personal disagreements as to their conclusions.
IV.
A.
Our Court was in the vanguard of courts to be persuaded that adherence to the Frye general acceptance standard as the sole test for assessing reliability of scientific expert testimony was unsatisfactorily constricting for fairly assessing reliability in certain areas of novel or emerging fields of science.
[T]oxic-tort litigation does not frequently encounter well-established and widely-accepted scientific theories of causation that can, at the level demanded by the scientific method, precisely delineate the causal path between the toxin and the pathology. Nevertheless, in such litigation there is often available data and information of a type that is used and relied on by experts in the field; further, there are reputable and highly qualified experts who, drawing on such data and information, have the proficiency to apply sound scientific methods sufficient to reach creditable opinions with respect to causation. We are thus strongly persuaded that a standard that accounts for those considerations should be employed to determine the reliability of expert opinion testimony relating to causation in toxic-tort litigation.
Accordingly, we hold that in toxic-tort litigation, a scientific theory of causation that has not yet reached general acceptance may be found to be sufficiently reliable if it is based on a sound, adequately-founded scientific methodology involving data and information of the type reasonably relied on by experts in the scientific field.
[Id. at 449 ,.] 593 A.2d 733
The Court further instructed courts to "consider whether others in the field use similar methodologies. 'What is necessary is that the expert arrived at his causation theory by relying upon methods that other experts in his field would reasonably rely upon in forming their own, possibly different opinions, about what caused the patient's disease.' "
In remanding to the trial court for re-evaluation of disallowed expert testimony, the Rubanick Court explained that the proper inquiry is not whether the expert thought his reliance on the underlying data from thirteen studies regarding exposure to a potential carcinogen was reasonable or whether the trial court thought that reliance was reasonable; rather, the proper inquiry is whether comparable " 'experts in the field [would] actually rely' on
One year later, in Landrigan, Justice Pollock, writing for the Court, applied the same approach and again remanded for a hearing on the disputed epidemiologic testimony about asbestos and colon cancer.
Moreover, Landrigan provided suggested tools for trial courts to use in rendering gatekeeping determinations about the reliability of an expert's methodology when the ultimate scientific opinion is not itself generally accepted. Landrigan explains that "[d]efined landmarks guide a trial court in making this determination. Support may be demonstrated by reference to professional journals, texts, conferences, symposia, or judicial opinions accepting the methodology."
Not long after those dual holdings by our Court, the Supreme Court issued its seminal Daubert opinion in 1993 pronouncing that Frye had been superseded by the adoption of the Federal Rules of Evidence.
Tying the principles together, the Court fashioned a new standard:
Faced with a proffer of expert scientific testimony ... the trial judge must determine at the outset ... whether the expert is proposing to testify to (1) scientific knowledge that (2) will assist the trier of fact to understand or determine a fact in issue. This entails a preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and of whether that reasoning or methodology properly can be applied to the facts in issue.
[Id. at 592-93 ,(footnotes omitted).] 113 S.Ct. 2786
The Court based that standard on the concept that the Federal Rules regarding expert testimony are "premised on an assumption that the expert's opinion will have a reliable basis in the knowledge and experience of his discipline."
In sum, the Court described the trial court's task as a "flexible" inquiry into the scientific principles at issue, ibid., one whose "overarching subject is the scientific validity -- and thus the evidentiary relevance and reliability -- of the principles that underlie a proposed submission,"
The Supreme Court elaborated on its Daubert standard for assessing reliability with two cases which, combined, round out the Daubert trilogy.
In General Electric Co. v. Joiner, the Court held that an abuse of discretion standard applies when reviewing a trial court's decision to admit or exclude expert testimony, even where that determination may be outcome determinative.
In Kumho Tire Co. v. Carmichael, the Court extended the Daubert approach to technical and other specialized knowledge admissible as expert testimony under Federal Rule of Evidence 702.
Importantly, the Court in Kumho emphasized again that the Daubert standard is flexible, explaining that (1) the Daubert factors do not necessarily apply "to all experts or in every case," id. at 141,
Ultimately, Kumho underscores that the objective of Daubert's gatekeeping requirement "is to make certain that an expert, whether basing testimony upon professional studies or personal experience, employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field." Id. at 152,
Federal Rule of Evidence 702 was amended in 2000 to reflect the Supreme Court's trilogy of cases outlining the Daubert standard. See, e.g.,
A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:
(a) the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and methods; and
(d) the expert has reliably applied the principles and methods to the facts of the case.
[ Fed. R. Evid. 702.]
A majority of states have adopted some form of the Daubert standard, either explicitly or implicitly. See, e.g.,
C.
In 2002, after the Daubert trilogy, we revisited the topic of the trial court's gatekeeping role under our current N.J.R.E. 702.
In Kemp,
The Kemp decision further holds that a trial court has an independent obligation to ensure that plaintiffs have sufficient
We note, in concluding this section, that the Kemp Court observed in 2002 that New Jersey had not amended N.J.R.E. 702 to include "the three-factor test for the admissibility of expert testimony that is part of the Federal rule as amended in response to Daubert."
V.
We intend by this case to clarify and reinforce the proper role for the trial court as the gatekeeper of expert witness testimony. Defendants and several amici have good reason to ask for clarification of the judicial gatekeeping role to be performed in New Jersey courtrooms.
When this Court modified the general acceptance standard to adopt a more relaxed approach for causation expert testimony in toxic tort litigation, and later for all medical cause-effect expert testimony, it envisioned the trial court's function as that of a gatekeeper -- deciding what is reliable enough to be admitted and what is to be excluded. Those are not credibility determinations that are the province of the jury, but rather legal determinations about the reliability of the expert's methodology. We now reinforce
Charged with determining whether to admit expert testimony, the trial court is responsible for advancing the
In Rubanick, we said that the court must ensure compliance with the requirement of "some expert consensus that the methodology and the underlying data are generally followed by experts in the field."
The gatekeeping role requires care. The process of making such determinations is "complicated," and we knew it would be "difficult." Rubanick,
Difficult as it may be, the gatekeeping role must be rigorous. In resolving issues of reliability of an expert's methodology in a new and evolving area of medical causation, we cautioned that "the trial court should not substitute its judgment for that of the relevant scientific community. The court's function is to distinguish scientifically sound reasoning from that of the self-validating expert, who uses scientific terminology to present unsubstantiated personal beliefs."
That said, we can and should have more clear direction to courts on how the gatekeeping function is properly performed. Recognizing proper gatekeeping when it is performed provides a discernible pathway for other courts to follow. We endeavor to do that with this matter. We add further clarification and assistance to trial courts, concerning performance of the gatekeeping role, when reviewing scientific expert testimony involving medical causation issues in civil matters, later in this opinion
VI.
In turning back to the matter before us to consider the trial court's exclusion of plaintiffs' experts' testimony, we begin by addressing the appropriate standard of review.
A reviewing court must apply an abuse of discretion standard to a trial court's determination, after a full Rule 104 hearing, to exclude expert testimony on unreliability grounds. Hisenaj v. Kuehner,
The Appellate Division stated that, although a trial court's decision to admit or exclude evidence is subject to an abuse of discretion standard, a reviewing court owes "somewhat less deference to a trial court's determination" regarding expert testimony. In re Accutane,
That proposition has, to date, carried weight in the context of a court applying the general acceptance test in a criminal matter, see State v. Harvey,
We reaffirm that the abuse of discretion standard applies in the appellate review of a trial court's determination to admit or deny scientific expert testimony on the basis of unreliability in civil matters. We now apply that standard to the determination of the trial court in this matter.
B.
An expert must demonstrate the validity of his or her reasoning. Landrigan,
Both Doctors Madigan and Kornbluth employed a methodology whereby they disregarded eight of nine epidemiological studies and relied on case reports and animal studies to support their opinion. It is clear that case reports are "at the bottom of the
As for the one study on which they did rely -- Sivaraman -- plaintiffs' experts disagreed with the authors' ultimate conclusions
The many contradictions in the experts' methodology were not lost on the trial court, which concluded that experts in the scientific community would not accept as consistent with scientific norms a methodology such as that used by plaintiffs' experts. In particular, the court found the methodology unsound because it relied on Sivaraman and Pimentel to the exclusion of other evidence. The trustworthiness of plaintiffs' experts' methodology was further undermined by internal inconsistencies, including the experts' refusal to examine the Rashtak and Fenerty studies on the ground that those studies did not report specific data for
The trial court reasoned that the overall approach taken by Dr. Kornbluth -- rejecting the evidence from the epidemiological studies, which all found no causal association, and proffering his own alternative opinion that a causal association was present based on lesser forms of evidence -- was based on an unsound methodology. That conclusion comports with the decisions of many other courts that experts cannot selectively choose lower forms of evidence in the face of a large body of uniform epidemiological evidence. See, e.g., In re Lipitor,
Finally, it bears noting that Dr. Kornbluth organized his testimony to support his personal view that a causal association existed
In sum, the trial court explained its reasons for concluding that plaintiffs' experts deviated from core scientific principles and strayed from their own claimed methodology in order to reach their conclusions. That the trial court deemed their testimony to be unreliable and excluded it from being presented is unsurprising. Ample evidence in the record supports that conclusion. Applying the abuse of discretion standard and the principles of Rubanick, Landrigan, and Kemp, we conclude that the trial court's determination is unassailable. The Appellate Division judgment, reversing the trial court's exclusion of the expert testimony, is reversed.
VII.
The divergent outcomes reached by the Appellate Division and the trial court in this matter provoked the debate among the parties and amici over whether our case law on the gatekeeping function is in need of clarification. Further, we are asked to consider adopting the Daubert standard, or to at least incorporate use of its factors, as a means to bring greater consistency to the gatekeeping function.
First, in respect of the gatekeeping role, we emphasize that we expect the trial court to assess both the methodology used by the expert to arrive at an opinion and the underlying data used
It is not for a trial court to bless new "inspired" science theory; the goal is to permit the jury to hear reliable science to support the expert opinion. Cf. Rosen v. Ciba-Geigy Corp.,
Importantly, Daubert identified a non-exhaustive list of factors for courts to consider using, if helpful, when it expanded on its test for assessing the reliability of scientific expert testimony. See
1) Whether the scientific theory can be, or at any time has been, tested;
2) Whether the scientific theory has been subjected to peer review and publication, noting that publication is one form of peer review but is not a "sine qua non";
3) Whether there is any known or potential rate of error and whether there exist any standards for maintaining or controlling the technique's operation; and
4) Whether there does exist a general acceptance in the scientific community about the scientific theory.
That last consideration -- general acceptance in the scientific community -- continues to have a bearing because, minimally, it permits the identification of a relevant scientific community and facilitates an express determination of a particular degree of acceptance within that community, or contrarily permits a technique with minimal support to be viewed with skepticism. See
We are persuaded that the factors identified originally in Daubert should be incorporated for use by our courts. The factors dovetail with the overall goals of our evidential standard and would provide a helpful -- but not necessary or definitive -- guide for our courts to consider when performing their gatekeeper role
In adopting use of the Daubert factors, we stop short of declaring ourselves a " Daubert jurisdiction." Like several other states, we find the factors useful, but hesitate to embrace the full body of Daubert case law as applied by state
First, we have already broadened our approach to testing for the reliability of expert testimony for certain areas in civil law, see Kemp,
Our view of proper gatekeeping in a methodology-based approach to reliability for expert scientific testimony requires the proponent to demonstrate that the expert applies his or her scientifically recognized methodology in the way that others in the
Importantly, that approach -- namely, to determine whether the scientific community would accept the methodology employed by plaintiffs' experts and would use the underlying facts and data as did plaintiffs' experts -- was employed by the trial court here. We approve of the court's methodological analysis. There was no encroachment on the factfinding function here. The trial court did the type of rigorous gatekeeping that is necessary when faced with a novel theory of causation, particularly one, as here, that flies in the face of consistent findings of no causal association as determined by higher levels of scientific proof.
For all the reasons expressed herein, we conclude that the trial court's exclusion of plaintiffs' experts' testimony was well-supported and well-reasoned. There was no abuse of discretion by the trial court in its evidential ruling.
VIII.
We reverse the judgment of the Appellate Division, which had reversed the trial court's exclusion of plaintiffs' experts' testimony.
CHIEF JUSTICE RABNER and JUSTICES ALBIN, FERNANDEZ-VINA, SOLOMON, and TIMPONE join in JUSTICE LaVECCHIA's opinion. JUSTICE PATTERSON did not participate.
Notes
Frye v. United States,
Daubert v. Merrell Dow Pharms., Inc.,
As noted in the Appellate Division's opinion in this matter, this case is one of many mass tort cases spanning over a decade relating to Accutane. In re Accutane Litig.,
Three sections of the Reference Manual are relevant to this appeal: the Reference Guide on Statistics, by David H. Kaye and David A. Freedman; the Reference Guide on Epidemiology by Michael D. Green et al.; and the Reference Guide on Medical Testimony by John B. Wong et al. For ease of reference, we refer to the Reference Manual as a single document.
As the Reference Manual explains, a randomized trial is performed by randomly assigning study subjects into one of two groups: one group is exposed to the agent in question and the other group is not. Id. at 555. The group not exposed to the agent is given a placebo, an inactive ingredient. Ibid. The feasibility of such studies is often limited due to the potentially harmful side effects associated with a particular agent. Ibid.
The guidelines initially were proposed by the Surgeon General in 1964 and were later expanded upon by Sir Austin Bradford Hill in 1965. Reference Manual at 600.
Charles N. Bernstein et al., Isotretinoin is Not Associated with Inflammatory Bowel Disease: A Population-Based Case-Control Study, 104 Am. J. Gastroenterol. 2774 (2009).
Seth D. Crockett et al., Isotretinoin Use and the Risk of Inflammatory Bowel Disease: A Case-Control Study, 105 Am. J. Gastroenterol. 1986 (2010).
Mahyar Etminan et al., Isotretinoin and Risk for Inflammatory Bowel Disease, 149 JAMA Dermatol. 216 (2013).
A meta-analysis is a form of epidemiological study whereby the study authors pool separate studies together and then interpret the results. See Reference Manual at 289.
Raed O. Alhusayen et al., Isotretinoin Use and the Risk of Inflammatory Bowel Disease: A Population-Based Cohort Study, 133 J. Investigative Dermatol. 907 (2013).
Sarah Fenerty et al., Impact of Acne Treatment on Inflammatory Bowel Disease, 68 J. Am. Acad. Dermatol. AB5 (2013).
Shadi Rashtak et al., Isotretinoin Exposure and Risk of Inflammatory Bowel Disease, 150 JAMA Dermatol. 1322 (2014).
Antoine Racine et al., Isotretinoin and Risk of Inflammatory Bowel Disease: A French Nationwide Study, 109 Am. J. Gastroenterol. 563 (2014).
Mark Pimentel et al., Identification of a Prodromal Period in Crohn's Disease but Not Ulcerative Colitis, 95 Am. J. Gastroenterol. 3458 (2000).
S.M. Barratt et al., Prodromal Irritable Bowel Syndrome May Be Responsible for Delays in Diagnosis in Patients Presenting with Unrecognized Crohn's Disease and Celiac Disease, but Not Ulcerative Colitis, 56 Dig. Dis. Sci. 3270 (2011).
As plaintiffs' experts explained, a point estimate serves as a way to calculate a single value for a sample of data and is the researchers' "best guess" as to the level of risk of a specific health effect from the substance being studied. A point estimate of 1.0 is indicative of no effect; a point estimate above 1.0 is indicative of increased risk; and a point estimate below 1.0 is indicative of decreased risk. For more information, see generally Reference Manual at 292. We note that the experts in this case do not distinguish between the term "point estimate" and the related concepts of "relative risk" and "odds ratio." For a discussion of those concepts, see generally id. at 566-69.
As plaintiffs' experts explained, statistical significance is measured through use of a confidence interval, which reflects a range of possible values calculated from the results of a particular study. A confidence interval that ranges from below 1.0 to above 1.0 is considered not to be statistically significant. Thus, even where a study's point estimate is indicative of either a decreased or increased risk, that result would not be considered statistically significant if the confidence interval ranges both above and below 1.0. On the other hand, a study will be considered statistically significant where the confidence interval is entirely above or entirely below 1.0. For more information, see generally Reference Manual at 574-83, 621.
To summarize his detailed explanation, Dr. Kornbluth asserts that retinoic acid, a breakdown product of Accutane, marks inflammatory cells known as "T cells" with a compound known as "alpha 4 beta 7." That binding process allows the inflammatory T-cells to then travel through the digestive tract and bind to another receptor known as "MadCAM." The process of inflammatory T-cells traveling through the digestive tract and binding to the other receptors on the intestinal wall then creates the inflammation that results in Crohn's disease. He also explained that two drugs currently used in treating Crohn's disease -- vedolizumab and natalizumab -- are believed to work by blocking alpha 4 beta 7 from binding to the T-cells.
As Dr. Madigan explained, a power analysis examines for the risk that a study's outcome was a "false negative."
Deepa Reddy et al., Possible Association Between Isotretinoin and Inflammatory Bowel Disease, 101 Am. J. Gastroenterol. 1569 (2006).
V. Chouraki et al., The Changing Pattern of Crohn's Disease Incidence in Northern France: a Continuing Increase in the 10-to 19-Year-Old Age Bracket (1988-2007), 33 Aliment. Pharmacol. Ther. 1133 (2011).
The trial court's determination was based solely on plaintiffs' experts' methodology. The experts' credentials were not in issue at any point.
As Frye garnered considerable criticism through the years, the United States Supreme Court ultimately resolved a split among the circuit courts and held that Frye was superseded by the adoption of the Federal Rules of Evidence. Daubert,
The Court also acknowledged that other evidence rules pertain in the analysis in addition to Rule 702, including Rules 703 and 403.
In 1992, this Court adopted N.J.R.E. 702 to replace Evidence Rule 56(2) and tracked the language of the then-existing version of Federal Rule of Evidence 702. The Official Comment to N.J.R.E. 702 notes that our Rule followed the then-existing federal rule verbatim, with a minor language change.
The trial court explained that the Sivaraman study appeared only as an abstract in the American Journal of Gastroenterology, and a written report detailing the study's findings has never been published. As defendants noted, the study remains unpublished today, and it has not been cited in any published opinion other than the present case.