Lead Opinion
Opinion for the Court filed by Circuit Judge ROGERS.
Dissenting opinion filed by Circuit Judge. HENDERSON.
This case appears before this court for the second time after the district court granted summary judgment to appellees, Dr. Jorge Labarraque and the Upjohn Company. Again, we address only the question of the admissibility, not the weight, of the Ambro-sinis’ expert evidence. The district court initially ruled that the Ambrosinis had failed to present admissible scientific evidence sufficient to create a genuine issue of material fact as to whether the drug Depo-Provera caused the birth defects suffered by Teresa Ambrosini, the daughter of Mr. and Mrs. Ambrosini. This court reversed summary judgment and remanded the ease to afford the district court the opportunity to determine whether the opinions expressed by the Ambrosinis’ medical experts had an adequate legal foundation to render them admissible under Federal Rule of Evidence 703. Ambrosini v. Labarraque,
The Ambrosinis contend that the district court erred in refusing to accept at “face value” Dr. Allen S. Goldman’s uneontrovert-ed testimony that his conclusion concerning specific causation was based upon a valid scientific methodology. They also contend that the district court’s ruling was contrary to Ferebee v. Chevron Chemical Co.,
I.
Teresa Ambrosini'was bom on October 23, 1967, with severe birth defects, including facial and ear malformations, hearing loss due to middle ear abnormalities, eye and vertebral malformations, and cleft lip and palate. In 1984, Teresa and her parents sued the manufacturers of the drugs Bendectin and Depo-Provera claiming that the drugs, either individually or in combination, caused Teresa’s birth defects. The Ambrosinis also named as a defendant Mrs. Ambrosini’s physician, Dr. Labarraque, who prescribed the drags for Mrs. Ambrosini during her pregnancy. The claims against the manufacturer of Bendectin were dismissed in 1989, leaving only the prescribing physician and the Upjohn Company as defendants.
Upjohn moved for summary judgment on the ground that no reliable scientific evidence existed to support the contention that Depo-Provera caused Teresa’s birth defects. In support of its motion, Upjohn submitted the affidavit of Dr. Joe Leigh Simpson, who discussed three epidemiological studies, as well as other published articles and studies, all indicating that medroxyprogesterone (the generic name for Depo-Provera) did not cause the type of birth defects suffered by Teresa Ambrosini. In response, the Ambrosinis
In reversing the grant of summary judgment, this court explained that Federal Rule of Evidence 705 “eliminates the prior practice. of requiring an expert to set out, specifically, the facts and data underlying an opinion before allowing the expert to testify.” Ambrosini I,
On remand, the district court issued orders to show cause requiring the Ambrosinis’ experts to produce the articles and other data that formed the basis of their opinions, and then held an evidentiary hearing. Thereafter, the district court ruled that the testimony of Dr. Goldman was inadmissible under Daubert v. Merrell Dow Pharmaceuticals,
II.
Our review of the grant of summary judgment is de novo. Anderson v. Liberty Lobby, Inc.,
The Daubert standard involves a two-prong analysis that centers on evidentia-ry reliability and relevancy: the district court must determine first whether the expert’s testimony is based on “scientific knowledge;” and second, whether the testimony “will assist the trier of fact to understand or determine a fact in issue.” Id. at 592,
Under the first prong of the analysis, the district court’s focus is on the methodology or reasoning employed. “ ‘[Scientific’ implies a grounding in the methods and procedures of science,” and “ ‘knowledge’ connotes more than subjective belief or unsupported speculation.” Id. at 590,
[I]n order to qualify as “scientific knowledge,” an inference or assertion must be derived by the scientific method. Proposed testimony must be supported by appropriate validation — i.e., “good grounds,” based on what is known. In short, the requirement that an expert’s testimony pertain to “scientific knowledge” establishes a standard of evidentiary reliability.
Id.
The Court discussed four factors that the district court may consider in evaluating
The second prong of the Daubert analysis primarily concerns relevance. Id. at 591,
This court has had only one occasion to consider the Daubert standard. In Joy v. Bell Helicopter Textron, Inc.,
Even if the burden placed on the “gatekeeper” may seem heavy at times, see, e.g., Daubert,
III.
In response to Upjohn’s motion for summary judgment, which asserted that there was no reliable scientific evidence supporting the contention that Depo-Provera causes the type of congenital defects with which Teresa was born, the Ambrosinis proffered a two-pronged response: the first, by Dr. Strom, an epidemiologist, to show that the drug could cause birth defects like Teresa’s; the second, by Dr. Goldman, a teratologist, to show that the drug, in his opinion, had caused Teresa’s birth defects. So understood, the Ambrosinis presented experts on both general and specific causation to meet their burden to defeat summary judgment. See Mendes-Silva,
A.
Dr. Strom, the epidemiologist, offered testimony addressing the general causal link between Depo-Provera and the type of birth defects with which Teresa was bóm. Without addressing the first prong of the Daubert analysis, the reliability of Dr. Strom’s methodology, the district court ruled that his testimony was inadmissible because it did not meet the second prong, the relevancy or “fitness” of the testimony. In conducting the relevance inquiry, the district court adopted a standard articulated by the Ninth Circuit on remand from the Supreme Court’s decision in Daubert. Daubert v. Merrell Dow Pharmaceuticals, Inc.,
Under Daubert, Dr. Strom’s evidence does not warrant exclusion simply because it fails to establish the causal link to a specified degree of probability. The fitness prong of the Daubert admissibility inquiry primarily concerns relevance. The disposi-tive question is whether the testimony will “ ‘assist the trier of fact to understand the evidence or to determine a fact in issue,”’ Daubert,
Dr. Strom’s testimony also survives the first stage of Daubert scrutiny, which requires that the expert evidence constitute scientific knowledge.
Dr. Strom proceeded to explain how he arrived at his opinion that a positive causal connection exists between Depo-Provera and the type of birth defects suffered by Teresa. Emphasizing that epidemiologists evaluate the “totality of the data,” Dr. Strom stated that he “conducted [an] extensive search of the entire medical literature in terms of the epidemiology of the link between progestins and birth defects, reviewed every paper that is relevant to this in the medical literature, and applied absolutely, conventional epidemi-ologieal methods and criteria to draw conclusions of causation.” In order to determine epidemiologic causation, he explained, the epidemiologist first determines whether there is an “association” between two phenomena, that is, “whether there is a statistically significant finding at greater than 95 percent chance that it’s not due to random error.” Upon finding an association, he continued, epidemiologists then apply specific criteria to determine whether that association is causal. Dr. Strom recited and explained these criteria, which include consistency in the findings of multiple scientific studies, biologic plausibility, the time sequence of the prospective cause and effect, the quantitative strength of the association, and the specificity with which the two phenomenon correlate. After finding an association between Depo-Provera and the types of birth defects suffered by Teresa, Dr. Strom stated that he also found consistency among the relevant scientific studies, with the exception of those negative studies which he discounted as too small to be significant, and biological plausibility. Dr. Strom testified that he did not recalculate data from other studies,
While publication in a peer-reviewed journal is not dispositive in evaluating whether an opinion is based on scientific knowledge, Daubert,
B.
The district court also ruled inadmissible Dr. Goldman’s testimony that, within a reasonable degree of medical certainty, Depo-Provera can and did in fact cause Teresa’s birth defects. While noting that Dr. Goldman’s testimony passed the relevance prong of the Daubert test, the district court concluded that it failed to qualify as scientific knowledge. The district court essentially found fault with Dr. Goldman’s testimony for two reasons. First, as to general causation, the court took issue with Dr. Goldman’s conclusion that Depo-Provera can cause birth defects. Reviewing the studies presented by Upjohn that suggest the absence of a causal relationship, the court stated that Dr. Goldman “has never specified the basis for his disagreement.” While Dr. Goldman rejects the negative studies showing no causal relationship, the court continued, he offered no basis for his conclusion that causation did in fact exist. The court also faulted him for founding his conclusion on a balaneing-of-the-competing-arguments methodology, an approach the court concluded was not based on scientific knowledge. Second, as to specific causation, the court emphasized that Dr. Goldman failed to elaborate the methodology he used to move from the conclusion that Depo-Provera can cause birth defects to the conclusion that Depo-Provera actually caused Teresa’s birth defects. With regard to excluding other potential causes, the court stated, “Dr. Goldman gave no recitation of steps he took, other than reviewing Teresa Ambrosini’s medical records, to ensure that no other factors may have caused [her] birth defects.”
The district court miseharacterized Dr. Goldman’s testimony on general causation when it stated that the only description of his methodology was that he reviewed data and then performed a balancing analysis. In reaching this conclusion, the court “relied heavily on an isolated comment” about balancing rather than, as this circuit requires, “a fair reading of [Dr. Goldman’s] entire [statement].” Mendes-Silva,
Under the relevant precedent in this circuit, Dr. Goldman’s testimony is ad
It is true that the expert evidence offered by Dr. Goldman in the instant case bears some resemblance to that proffered in Richardson,
Second, unlike in Richardson, there is no “overwhelming body of contradictory epidemiological evidence” to Dr. Goldman’s conclusion.
Third, unlike the doctor in Richardson, whose opinions were based on his own unre-viewed recalculations of data gathered by others,
Consistent with the Daubert Court’s instruction that the admissibility inquiry is a flexible one and may include consideration of factors beyond those discussed by the Court, see Daubert,
Also, Dr. Goldman is an expert with significant stature and expertise in the area of birth defects. He is the current director of The Craniofacial Center at the University of Illinois College of Medicine and the former director of the section of teratology at the Children’s Hospital of Philadelphia, has served on numerous occasions as a consultant to the National Institute of Health in the fields of teratology and toxicology, and has published over two hundred articles in the field. While such evidence usually goes to whether an expert has sufficient qualifications to testify, several circuits have treated it as circumstantial evidence as to whether the expert employed a scientifically valid methodology or mode of reasoning. See Joiner,
The district court also mischaracterized Dr. Goldman’s testimony on specific causation. Contrary to the district court’s conclusion, the record shows that Dr. Goldman did elaborate upon the methodology that he used to get from the conclusion that Depo-Prov-era can cause Teresa’s type of birth defects to the conclusion that it did cause her defects. Dr. Goldman explained that he considered the other possible causes for Teresa’s condition, including chromosomal abnormalities, genetic defects, and viruses, and by reviewing Teresa’s and her mother’s medical records, he ruled them out. ■ He eliminated chromosomal abnormalities by consulting a chromosomal study of Teresa , that was done in the 1970’s; and ruled out a genetic defect by examining the Ambrosinis’ family history, consulting the genetic literature, reviewing the general medical history and physical examinations set out in the medical records'of Teresa and her mother, and by reviewing the individual malformations in this case. Dr. Goldman added that he eliminated single gene mutations as a possible cause because “there are no described gene defects that produce this.” In ruling out a virus, Dr. Goldman explained that there are “about a half dozen viruses” known to cause birth defects, and that, if a virus were responsible for defects, the mother would have had the viral disease. After consulting the mother’s history, Dr. Goldman found that the clinical picture did not indicate that a virus was responsible.
Upjohn’s efforts to discredit Dr. Goldman’s methodology by pointing to the limits of the research he undertook into possible genetic or chromosomal causes of Teresa’s birth defects — namely, that he had neither done a critical family history nor ordered a more state-of-the-art chromosomal study — goes to the weight rather than the admissibility of his testimony. In Mendes-Silva, where the expert testified that he had ruled out alternative non-viral causes for the plaintiffs injury by consulting the examinations and lab tests conducted on the plaintiff while she was in the hospital, this court found no fault with partial reliance on such a methodology. Mendes-Silva,
Under Rule 703, Daubert instructs that the admissibility inquiry focuses not on conclusions, but on approaches, and the record shows that both Drs. Strom and Goldman employed scientifically valid methodologies. Both doctors’ testimony comfortably cleared the hurdle of admissibility established by Daubert and by this circuit’s precedents concerning expert scientific evidence. Their conclusions were neither the “subjective belief’ or “unsupported speculation” that Dau-bert and the Federal Rules would preclude a fact finder from hearing, nor the admittedly deficient expert opinions excluded by this court in Richardson,
Accordingly, we reverse the grant of summary judgment to Upjohn and remand the case to the district court for further proceedings.
Notes
. For ease of reference, we refer hereinafter to appellees as Upjohn.
. Whereas an epidemiologist studies the distribution and determinants of disease in populations, a teratologist studies abnormal development and congenital malformations in animals and human beings.
. Federal Rule of Evidence 702 provides:
If 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.
. Federal Rule of Evidence 703 provides:
The 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.
. Federal Rule of Evidence 402 provides:
All relevant evidence is admissible, except as otherwise provided by the Constitution of the United States, by Act of Congress, by these rules, or by other rules prescribed by the Supreme Court pursuant to statutory authority. Evidence which is not relevant is not admissible.
.See also Joiner v. General Electric Co.,
. See, e.g., Joiner,
. Under the Ninth Circuit’s standard, a plaintiff must offer either specific evidence that the drug actually caused their injuries or epidemiological proof that the drag “more than doubles’’ the risk of birth defects because epidemiological evidence presents statistical likelihoods rather than direct information about the cause of birth defects for the particular plaintiff. Id. at 1320-21. In light of our disposition, we have no occasion to consider whether the substantive tort law of California and the District of Columbia are similar and need not decide whether to adopt the Ninth Circuit’s analysis in Daubert II when causation is to be established solely by the testimony of an epidemiologist.
. Dr. Strom clarified that to the degree that the author of a study did the calculation, he preferred and used the author's calculations. Only when the author presented data on a question, but did not present the relevant calculations, did Dr. Strom do them himself. Never did he recalculate the author's own calculations on an issue.
. In originally granting summary judgment, the district court stated that it gave "significant weight” to the view expressed by the F.D.A. in 1989 that there is no causal relationship between progestational agents and non-urogenital defects, and that previously required package label warnings about possible congenital heart defects and limb reduction defects were no longer necessary. 53 Fed.Reg. 1243 (Jan. 12, 1989). However, both Drs. Strom and Goldman testified, and it was undisputed by Upjohn, that before 1989 the F.D.A. had placed Depo-Provera in category X, a classification of drugs that are prohibited from use during pregnancy because of known effects on offspring exposed in útero.
. The Ambrosinis' reliance on Fireguard, Sprinkler Sys. v. Scottsdale Ins. Co.,
. We do not suggest that an independent source was necessary to support the admissibility of Dr. Goldman’s testimony.
. In dismissing Dr. Strom’s and Dr. Goldman’s opinions on general causation, the dissent misinterprets their testimony, ignoring their discussion of statistical power and the appropriateness of evaluating the totality of the data, see infra at 141-143. Dr. Strom and Dr. Goldman did not, as the dissent asserts, infra at 141-142, base their opinions largely on two independent studies by Greenberg and Matsunaga. Dr. Strom testified that he relied on those studies “among many” and that he examined the "totality of the data,” not simply “a few papers.” Dr. Goldman’s reference to the Greenberg and Mat-sunaga studies was in response to a question regarding studies that had been published in a peer-reviewed journal where the authors found statistically significant increased risks for proges-tin alone and cleft lip and palate; he did not purport to be enumerating the most important studies or the ones on which he primarily relied. Dr. Strom testified that the Greenberg study found a “trend" between progestagens and the increased incidence of birth defects, but lacked sufficient statistical power to find a statistically significant association. Moreover, Dr. Strom conceded that the Matsunaga study concluded that, the association it found between hormone therapy and birth defects could not have been causal because the hormones were administered after the defective organs had already developed; he did not, however, concede that the study concluded hormone therapy does not cause birth. defects. In discussing studies by Heinonen and Newman, Dr. Goldman clarified that they did not specifically discuss cleft lip and palate because "they didn’t have enough cases of cleft lip and cleft palate to say one way or the other." "But,” Dr. Goldman continued, “they did have enough if they grouped the data altogether to say that ... progestins produced a significant malformation rate in the total amount [of defects].” In like manner, contrary to the dissent's suggestion otherwise, see infra at 142, Dr. Strom did not concede that the Heinonen study found no association between Depo-Provera and -the types of birth defects from which Teresa suffers. After noting that Heinonen found “associations between progestins in general and all defects and [an] association between progestins and congenital heart defects” and was "specifically able to identify an association between Provera and birth defects which it did not see with some of the other progestins,” Dr. Strom clarified that "the fact that it didn't see an association between Provera and one specific defect” was inconclusive because "then you're getting down to such fine divisions that you're not going to have any statistical power.” Similarly, in discussing Lam-mer's study, Dr. Strom noted that although it found no causal relationship between progestins and cleft lip or palate, it did find increased risk of other malformations. As to the review articles published by Warkany, Wilson and Brent, and Schardein, for which the authors simply reviewed the literature rather than conducting their own scientific studies, Dr. Strom noted that none were epidemiologists, and Dr. Goldman pointed out that these studies concluded "there wasn’t data sufficient to establish that progestins cause nongenital defects in humans,” not that there was "no evidence” of a causal relationship.
. In Porter, the excluded expert testimony was offered by a series of doctors, one of whom admitted having no scientific support for a "curbside” opinion on causation; another admit
Dissenting Opinion
dissenting:
In Daubert v. Merrell Dow Pharmaceuticals, Inc.,
in order to qualify as “scientific knowledge,” an inference or assertion must be derived by the scientific method. Proposed testimony must be supported by appropriate validation — i.e., “good grounds,” based on what is known. In short, the requirement that an expert’s testimony pertain to “scientific knowledge” establishes a standard of evidentiary reliability.
Both Strom and Goldman purported to base their opinions largely on two indepen
Goldman also claimed to rely on two studies by Heinonen and Newman. App 346. But again, responding to specific questions, he conceded that neither study “found a statistically significant increased risk for Prov-era causing the type of birth defects that Teresa Ambrosini has,” neither of “cleft lip and palate” nor of “the entire picture of what Teresa Ambrosini has.” App. 347-48.
Further, each expert acknowledged, but discounted, the existence of published studies of progestins (Lammer study) and Provera in particular (Katz study and Yovich study) that found no causal relationship between those substances and cleft lip or palate, App. 257, 259 (Strom); App. 350-51 (Goldman), and three other published studies (Warkany study, Wilson & Brent study, Sehardein study) that found no evidence that progestins cause nongenital birth defects. App. 295 (Strom); App. 402-04 (Goldman).
Thus, in the end, we are left with no basis for the two experts’ opinions except their own individual study. Strom testified that he formed his opinions “look[ing] at the totality of the data” in the published studies without “looking at the much larger literature of people expressing opinions in the literature.” App. 260. This “methodology” produced conclusions inconsistent with those of the studies’ authors but supportive of the appellants’ case. Strom claimed to base his opinions on the data of the “positive” studies only, rejecting the negative studies’ data as “too Small,” App. 266, but the two “positive” studies he identified do not support a causal relationship between Depo-Provera and any of the specific birth defects Teresa Ambrosini suffered. See App. 300, 293 (Heinonen study found association of progestins with “heart defects” but “didn’t see an association between Provera and one specific defect”); App. 257 (Lammer study “didn’t find an in
Goldman described his methodology as follows: “[L]ike anything else, it’s the preponderance of an argument. It’s the argument in favor against the argument against, and this is what everyone else does.” App. 429. The district court concluded: “The problem with this methodology is that it does not satisfy Daubert.” App. 89. I agree — as apparently does the majority. See Maj. Op. at 137.
The majority nevertheless attempts to defend Goldman’s baseless opinion on several grounds. First, the majority accuses the district court of “‘reifying] heavily on an isolated comment’ about balancing.” Maj. Op. at 137 (quoting Mendes-Silva v. United States,
The majority also observes that Goldman himself explained that he used the “traditional methodology of experts in the field.” Maj. Op. at 137, 138-139. Indeed he so stated repeatedly — without ever identifying or describing the methodology except as noted above. If such conclusory statements must be accepted at face value, as the majority suggests,' the Daubert standard becomes meaningless. Cf. Daubert v. Merrell Dow Pharmaceuticals, Inc.,
The majority similarly suggests that Goldman’s “significant stature and expertise in the area of birth defects” shows that he “employed a scientifically valid methodology or mode of reasoning.” Maj. Op. at 139-140. Daubert, however, requires that the expert’s testimony in a specific case satisfy “a standard of evidentiary reliability,”
The majority acknowledges the “resemblance” of Goldman’s testimony to “that proffered in Richardson [v.Richardson-Merrell, Inc.,
First, the majority states: “Dr. Goldman never conceded that his methodology was not generally accepted in his field ...” Maj. Op. at 138.
The majority next asserts that “unlike in Richardson, there is no ‘overwhelming body of contradictory epidemiological evidence to Dr. Goldman’s conclusion.’ ” Maj. Op. at 138 (quoting
Finally, the majority claims that “unlike the doctor in Richardson, whose opinions were based on his own unreviewed recalculations of data gathered by others,
In sum, the appellants’ expert testimony here was very much like the unfounded testimony in Richardson and falls far short of Daubert’s “scientifically valid” standard for admissibility. On remand, the district court
. Goldman did testify regarding the birth defects that were found in the two studies, "like cardiac defects, limb defects and several others,” that the researchers "did have enough if they grouped the data all together to say that Provera — no, no— progestins produced a significant malformation rate in the total amount.” App. 348^-9. This "significant malformation rate” tells us nothing, however, of the relationship between progestins and cleft lip or palate, which, as the majority concedes, the studies "did not specifically discuss ... because 'they didn’t have enough cases of cleft lip and cleft palate to say one way or the other.' " Maj. Op. at 139 n.13 (quoting Goldman at App. 348).
. Goldman also cited a letter to the editor of the “Medical Journal of Australia” that apparently found some association between"progestogen-es-trogen” combinations and cleft lip and palate. See App. 362-68. Goldman testified, however, that the letter was based on an "uncontrolled study" and as such "might give you some idea” but would not yield a result that is "significant statistically.” App. 365.
. The majority asserts that this was "a point that the Ambrosini I court suggested was dispositive in Richardson." Maj. Op. at 138. Ambrosini I, however, characterized Richardson as holding that the expert's testimony "was inadmissible under Rule 703 because he acknowledged that the data underlying his opinion was not of a type reasonably relied on by experts in the field.”
. When asked whether he recalculated statistics, Strom replied: "Generally if the data — if the calculations were in the paper, I preferred to take the calculations of the author. The only time we did calculations of our own, and there were some where we did, where we had questions we were looking at, the data were presented by the authors but they did not do the calculations." App. 224.
. The Ambrosini I panel stated:
[T]he court could have required Dr. Strom and Dr. Goldman to disclose the bases for their opinions so that it could determine whether the opinions had an adequate foundation (i.e. whether they were based on information that experts in the field would reasonably rely on in determining whether a particular drug causes birth defects). Only then could the court determine whether the affidavits were admissible under Rule 703. A court must know the basis for an expert's opinion before it can determine that the basis is not of a type reasonably relied on by experts in the field.
. Because there was no preliminary showing of general causation — by either expert — it is irrelevant whether Goldman adequately eliminated other possible causes, as the majority maintains, to establish specific causation. See Maj. Op. at 140. As the district court observed, Strom conceded he was not qualified to testify on the latter. See App. 31. Nor need we consider whether Strom's testimony "fit” the plaintiff's case, that is, in the words of rule 702, whether it would "assist the trier of fact to understand the evidence or to determine a fact in issue,” — a proposition the district court rejected. See App. 31-33; see also Daubert,
.Whether or not the district court "conflated the questions of the admissibility of expert testimony and the weight appropriately to be accorded such testimony by a fact finder,” as the majority asserts, Maj. Op. at 141, (and I do not so con- ■ cede) we can and should, nonetheless, affirm the court’s decision for the reasons I have given. See Haddon v. Walters,
