Full opinion text
MEMORANDUM OPINION AND ORDER SPARR, District Judge. Currently pending in this court are numerous silicone breast implant cases brought against various breast implant manufacturers. Plaintiffs seek damages for injuries they allege to have suffered from their silicone breast implants. Making claims under Colorado law for strict liability, negligence, and breach of warranty, Plaintiffs allege that their silicone breast prostheses have caused “auto-immune diseases” and have injured the Plaintiffs “in and about their body and extremities.” As of this date, only the Plaintiffs in Roberts v. Baxter, Civil Action No. 91-S-923 and Zelinger v. Baxter, Civil Action No. 93-S-2762 have filed their designations of expert witnesses. Numerous motions challenge the relevance and scientific reliability of the proffered testimony of the Plaintiffs’ expert witnesses regarding a causal connection between silicone gel breast implants and “auto-immune” or systemic diseases. The expert witnesses proffered by Plaintiffs Roberts and Zelinger are Dr. Stuart S. Kassan, M.D.; Dr. Jack Klapper, M.D.; Dr. Daniel Hoffman, M.D.; Dr. Robert Guidoin, Ph.D.; and Dr. Pierre Blais, Ph.D. This opinion addresses the following motions made by Defendants Baxter Healthcare Corporation, Minnesota Mining and Manufacturing Co., Bristol-Myers Squibb Co., Natural Y Surgical Specialties, Inc., Medical Engineering Corp., Surgitek, Inc., and Aesthetech Corp. (hereinafter “Defendants”): (1) the Defendants’ Motion to Exclude General Causation Testimony and Brief in Support (Science Brief (filed June 2,1997)); (2) the Defendants’ Motion In Limine to Exclude Expert Testimony of Stuart Kassan, M.D. (filed June 2,1997); (3) the Defendants’ Motion In Limine to Exclude Expert Testimony of Jack A. Klapper, M.D. (filed June 2,1997); (4) the Defendants’ Motion In Limine to Exclude Expert Testimony of Daniel Hoffman, M.D. (filed June 2,1997); (5) the Defendants’ Motion In Limine to Exclude Expert Testimony of Robert Guidoin, Ph.D. (filed June 2,1997); and (6) the Defendants’ Motion In Limine to Exclude Expert Testimony of Pierre Blais, Ph.D. (filed June 2,1997). The court has reviewed, inter alia, the motions, Plaintiffs’ Brief in Opposition (filed July 15, 1997), Defendants’ Reply Brief (filed August 8, 1997), the experts’ reports, the voluminous exhibits, affidavits, scientific studies, and scientific articles, the parties’ proposed findings of fact and conclusions of law (filed September 29, 1997), the supplemental deposition excerpt (filed September 29,1997), Plaintiffs’ seven notebooks of scientific studies (submitted September 8, 1997); Plaintiffs’ Summary of Science Articles (filed October 1, 1997), Defendants’ Response to Plaintiffs’ Summary of Science Articles (filed October 15, 1997), Defendants’ Supplemental Brief (filed January 21,1998), Plaintiffs’ Supplemental Brief (filed January 30, 1998), Plaintiffs’ supplement (filed February 25, 1998), Defendants’ Response (filed March 3, 1998), Defendants’ supplement (filed March 11, 1998), Defendants’ supplement (filed March 12, 1998), Defendants’ supplement (filed May 1, 1998), Defendant’s supplement (filed May 5, 1998), the entire case file, and the applicable law and is sufficiently advised in the premises. I. Standard of Review The Federal Rules of Evidence govern the admission of expert scientific testimony in a federal trial. Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993). Fed.R.Civ.P. 702, governing expert testimony, 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. Under the Rules, federal trial judges “must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable.” Daubert, 509 U.S. at 589, 113 S.Ct. 2786. The Plaintiffs have the burden of proving that the testimony of their expert witnesses is admissible pursuant to Fed. R.Evid. 702 and the standards set forth in Daubert, 509 U.S. at 579, 113 S.Ct. 2786, governing the admissibility of scientific evidence. Daubert, 43 F.3d 1311, 1316 (9th Cir.1995). In applying Rule 702, the trial court has the responsibility of acting as a gatekeeper. Daubert, 509 U.S. at 592-93, 113 S.Ct. 2786. “Faced with a proffer of expert scientific testimony, then, the trial judge must determine at the outset, pursuant to Rule 104(a), 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.” Daubert, 509 U.S. at 592, 113 S.Ct. 2786. “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.” Daubert, 509 U.S. at 592-93, 113 S.Ct. 2786. “Neither the difficulty of the task nor any comparative lack of expertise can excuse the judge from exercising the ‘gatekeeper’ duties that the Federal Rules impose_” General Electric Co. v. Joiner, — U.S. -, -, 118 S.Ct. 512, 520, 139 L.Ed.2d 508 (1997) (Breyer, J., concurring). Under the first prong of .the Daubert test for admissibility of expert testimony, “[t]he adjective ‘scientific’ implies a grounding in the methods and procedures of science. Similarly, the word ‘knowledge’ connotes more than subjective belief or unsupported speculation.” Daubert, 509 U.S. at 590, 113 S.Ct. 2786. The trial court’s obligation under Rule 702 and Daubert is to determine eviden-tiary reliability, that is, trustworthiness. 509 U.S. at 590 n. 9, 113 S.Ct. 2786. “In a case involving scientific evidence, evidentiary reliability will be based on scientific validity.” Daubert, 509 U.S. at 590 n. 9, 113 S.Ct. 2786. “[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 evi-dentiary reliability.” Daubert, 509 U.S. at 590, 113 S.Ct. 2786; accord Summers v. Missouri Pacific Railroad System, 132 F.3d 599, 603 (10th Cir.1997). [Tjhere are important differences between the quest for truth in the courtroom and the quest for truth in the laboratory. Scientific conclusions are subject to perpetual revision. Law, on the other hand, must resolve disputes finally and quickly. The scientific project is advanced by broad and wide-ranging consideration of a multitude of hypotheses, for those that are incorrect will eventually be shown to be so, and that in itself is an advance. Conjectures that are probably wrong are of little use, however, in the project of reaching a quick, final, and binding legal judgment — often of great consequence — about a particular set of events in the past. We recognize that, in practice, a gatekeeping role for the judge, no matter how flexible, inevitably on occasion will prevent the jury from learning of authentic insights and innovations. That, nevertheless, is the balance that is struck by Rules of Evidence designed not for the exhaustive search for cosmic understanding but for the particularized resolution of legal disputes. Daubert, 509 U.S. at 596-97, 113 S.Ct. 2786. The Supreme Court has provided some guidance for the task of determining scientific validity. Daubert sets forth several non-exhaustive factors to assist trial courts in determining whether a theory or technique constitutes “scientific knowledge” within the meaning of Rule 702, including whether the methodology, principles and reasoning underlying the proposed experts’ opinions: (1) can be and have been empirically tested; (2) have been subjected to peer review and publication; (3) have a known or potential rate of error; and (4) have gained general acceptance in the relevant scientific community. 509 U.S. at 593-594, 113 S.Ct. 2786. Rule 702’s second prong concerns relevancy, or “fit.” Daubert, 509 U.S. at 591, 113 S.Ct. 2786. “[T]he scientific knowledge must be connected to the question at issue.” In re Paoli R.R. Yard PCB Litig., 35 F.3d 717, 745 (3d Cir.1994), cert. denied sub nom., General Electric Company v. Ingram, 513 U.S. 1190, 115 S.Ct. 1253, 131 L.Ed.2d 134 (1995). The trial court “must ensure that the proposed expert testimony is ‘relevant to the task at hand,’ ... i.e., that it logically advances a material aspect of the proposing party’s case.” Daubert, 43 F.3d at 1315. “[T]he standard for fit is higher than bare relevance.” In re Paoli, 35 F.3d at 745. Scientific expert testimony introduces special dangers to the fact-finding process because it “can be both powerful and quite misleading because of the difficulty in evaluating it.” Daubert, 509 U.S. at 595, 113 S.Ct. 2786 (internal quotation marks and citation omitted). Therefore, federal judges must exclude proffered scientific evidence under Rule 702 unless they are convinced that it speaks clearly and directly to an issue in dispute in the ease, and that it will not mislead the jury. Daubert, 43 F.3d at 1321. The trial court must also look to Fed. R.Civ.P. 703 in determining the admissibility of expert testimony. Rule 703 also contemplates that the court will play a role in the assessment of expert testimony offered to a jury. Rule 703 provides that expert opinions based on otherwise inadmissible evidence are to be admitted only if the facts or data are “of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject.” An expert’s otherwise relevant opinion is only admissible under Rule 703 where the underlying data have sufficient probative force and reliability that a reasonable expert could base an opinion on them. Viterbo v. Dow Chemical Co., 826 F.2d 420, 422 (5th Cir .1987); see also In re: Agent Orange Product Liability Litig., 611 F.Supp. 1223 (E.D.N.Y.1985), aff'd, 818 F.2d 187 (2d Cir.1987), cert. denied, 487 U.S. 1234, 108 S.Ct. 2898, 101 L.Ed.2d 932 (1988). At a minimum, the court must assess the reliability and the relevance of the proffered expert testimony by determining whether the expert has the requisite qualifications to render an opinion under Rule 702, whether the expert used appropriate methodology in arriving at his or her opinions, whether the expert relied on facts or data of a type reasonably relied upon by experts in the particular field, and whether the testimony is relevant, that is, “fits” the facts of the case. II. Analysis Plaintiffs assert tort claims for negligence and strict liability, as well as claims for breach of express and implied warranty. In Colorado, “[i]n order to prevail on a tort claim, a plaintiff must prove by a preponderance of the evidence that a defendant committed an act which caused an injury to that plaintiff.” Renaud v. Martin Marietta Corp., 749 F.Supp. 1545, 1551 (D.Colo.1990), aff'd 972 F.2d 304 (10th Cir.1992). Plaintiffs premise many of their alleged injuries on the existence of various kinds of “atypical connective tissue disease” (“ACTD”). This “disease” allegedly manifests itself through a “constellation” of symptoms and is allegedly caused by an autoimmune response to silicone from breast implants. Plaintiffs’ claims implicate several areas of scientific study, including rheumatology, neurology, and epidemiology. A. General and Specific Causation Causation in toxic-tort cases is discussed in terms of general and specific causation. See e.g., Raynor v. Merrell Pharmaceuticals, Inc., 104 F.3d 1371, 1376 (D.C.Cir.1997). General causation is whether a substance is capable of causing a particular injury or condition in the general population, while specific causation is whether a substance caused a particular individual’s injury. In order to establish their claims, Plaintiffs “must show both general and specific causation — that is, that breast implants are capable of causing” the conditions complained of, and that “breast implants were the cause-in-fact” of the specific conditions. Kelley v. American Heyer-Schulte Corp., 957 F.Supp. 873, 875 (W.D.Tex.1997), appeal dismissed, 139 F.3d 899, 1998 WL 127822 (5th Cir.1998); see also Raynor, 104 F.3d at 1376 (holding that specific causation evidence is irrelevant where there is no general causation evidence indicating that Bendectin causes birth defects); Anderson v. Bristol-Myers Squibb Co., No. H-95-003, slip op. at 16-22 (S.D.Tex. April 20,1998); Hall v. Baxter Healthcare Corp., 947 F.Supp. 1387, 1412-13 (Courts “have recognized two' levels of causation: general causation (i.e., can silicone gel cause disease in anyone?) and specific causation (i.e, did silicone gel breast implants causé disease in this plaintiff?)”) (citations omitted); Jones v. United States, 933 F.Supp. 894, 900-01 (N.D.Cal.1996) (plaintiff must show both “general causation',” that defendant’s conduct increased likelihood of injury, and “specific causation,” that defendant’s conduct was probable, not merely possible, cause of injury), aff'd, 127 F.3d 1154 (9th Cir.1997); Rutigliano v. Valley Business Forms, 929 F.Supp. 779, 783 (D.N.J.1996) (“Plaintiffs case requires expert testimony to satisfy her burden with respect to both general causation and specific causation”) (citations omitted), aff'd, 118 F.3d 1577 (3d Cir.1997); In re Silicone Gel Breast Implants Products Liability Litig., 887 F.Supp. 1469, 1477 (N.D.Ala.1995) (noting distinction between general causation and specific causation); Snyder v. The Upjohn Co., No. 94-1826-GHK at 8 (C.D.Cal. May 20, 1997) (the only possible specific causes “are those for which general causation has already been established”). B. Epidemiology is the Best Evidence of Causation The diseases and symptoms allegedly associated with breast implants occur in non-implanted women as well as implanted women. Many of the conditions that Plaintiffs attribute to breast implants appear in the general population. Without a controlled study, there is no way to determine if these symptoms are more common in women with silicone breast implants than women without implants. “The most important evidence relied upon by scientists to determine whether an agent (such as breast implants) cause disease is controlled epidemiologic studies. Epidemiology can be viewed as the study of the causes of diseases in humans.” (Ory Affidavit, Exhibit A p. 7 to Defendants’ June 2, 1997 Science Brief). Therefore, epidemiological studies are necessary to determine the cause and effect between breast implants and allegedly associated diseases. A valid epidemiologic study requires that study subjects, eases, and controls are chosen by an unbiased sampling method from a definable population. Epidemiology is the best evidence of causation in the mass torts context. Linda A. Bailey, et al., Reference Guide on Epidemiology, REFERENCE MANUAL ON SCIENTIFIC EVIDENCE at 126 (1994) (“In the absence of an understanding of the biological and pathological mechanisms by which disease develops, epidemiological evidence is the most valid type of scientific evidence of toxic causation”) (citations omitted); see also Raynor, 104 F.3d at 1376 (non-epidemiological studies, “singly or in combination,” were “not capable of proving causation in human beings in the face of the overwhelming body of contradictory epidemiological evidence”) (citations omitted); Allen v. Pennsylvania Engineering Corp., 102 F.3d 194, 197 (5th Cir.1996) (affirming exclusion of plaintiffs’ non-epidemiological causation evidence because “the most useful and eonclu-sive type of evidence in a case such as this is epidemiological studies”); Elkins v. Richardson-Merrell, 8 F.3d 1068, 1073 (6th Cir.1993) (affirming summary judgment where plaintiff failed to raise a genuine issue of fact regarding causation in light of epidemiological evidence), cert. denied, 510 U.S. 1193, 114 S.Ct. 1299, 127 L.Ed.2d 651 (1994); Brock v. Merrell Dow Pharmaceuticals, Inc., 874 F.2d 307, 311 (5th Cir.) (“the 'most useful and conclusive type of evidence in a ease such as this is epidemiological studies”), modified, 884 F.2d 166 (1989), cert. denied, 494 U.S. 1046, 110 S.Ct. 1511, 108 L.Ed.2d 646 (1990); Lynch v. Merrell-National Laboratories, 830 F.2d 1190, 1193-97 (1st Cir.1987) (affirming summary judgment for Bendectin manufacturer where plaintiff offered only criticism of defendant’s epidemiological evidence with no epidemiological evidence of its own); Hall, 947 F.Supp. at 1403 (“[t]he existence or nonexistence of relevant epidemiology can be a significant factor in proving general causation in toxic tort cases”) (citations omitted); Conde v. Velsicol Chem. Corp., 804 F.Supp. 972, 1025-26 (S.D.Ohio 1992) (“[ejpidemiologic studies are the primary generally accepted methodology for demonstrating a causal relation between a chemical compound and a set of symptoms or a disease”), aff'd, 24 F.3d 809 (6th Cir.1994); In re Agent Orange Product Liability Litigation, 611 F.Supp. at 1231 (“[a] number of sound epidemiological studies have been conducted on the health effects of exposure to Agent Orange. These are the only useful studies having any bearing on causation”). The Tenth Circuit has cited with approval several pre-Daubert Bendectin cases recognizing the primacy of epidemiological evidence. Wilson v. Merrell Dow Pharmaceuticals, Inc., 893 F.2d 1149, 1154 (10th Cir.1990) (“This lack of epidemiological proof for the Wilsons’ claims is particularly significant in light of recent decisions of federal courts of appeals granting judgment n.o.v. for Merrell Dow based upon the absence of epidemiological evidence showing a causal relationship between Bendectin use and birth defects”) (citations omitted). Likewise, in Renaud, the trial court recognized that epidemiology is required in toxic tort cases “where collection of such evidence is possible.” 749 F.Supp. 1545, 1554 (D.Colo.1990) (“even if plaintiffs had been able to prove exposure by their direct evidence, they would have been required to submit epidemiological evidence in support of their causation contentions”), aff'd, 972 F.2d 304, 307 (10th Cir.1992) (noting that plaintiffs’ causation evidence “was not sufficiently reliable, being drawn from tests on non-human subjects without confirmatory epidemiological data”) (citations omitted). C. More-Probable-Than-Not Burden Means Plaintiffs Must Establish a Doubling of Risk Upon remand of Daubert, the Ninth Circuit focused on the crucial issue referenced by the Tenth Circuit in Wilson, 893 F.2d at 1154-55, and Renaud, 749 F.Supp. at 1554-55: whether expert witness opinion evidence is admissible when the available epidemiology does not demonstrate that the plaintiffs alleged injury was “more likely than not” caused by the defendant. 43 F.3d 1311, 1320-22 (9th Cir.1995), cert. denied, 516 U.S. 869, 116 S.Ct. 189, 133 L.Ed.2d 126 (1995). The Ninth Circuit defined the plaintiffs burden as follows: [Plaintiffs] must establish not just that their mothers’ ingestion of Bendectin increased somewhat the likelihood of birth defects, but that it more than doubled it— only then can it be said that Bendectin is more likely than not the source of their injury. In short, Daubert, 43 F.3d at 1320-22, Wilson, 893 F.2d at 1154-55, and Renaud, 749 F.Supp. at 1554-55, instruct that if the available body of epidemiology demonstrates that breast implants do not double the risk of any known disease, then plaintiffs’ causation evidence is inadmissible. There exists in the context of breast implanted women a “background rate” of injury; that is, the injuries of which the breast implant plaintiffs complain are not unique, but occur frequently in women without breast implants. Hall, 947 F.Supp. at 1402; In re Breast Implant Cases, 942 F.Supp. 958, 960-61 (E.&S.D.N.Y.1996). Because the injuries of which Plaintiffs complain occur commonly in women without breast implants, Plaintiffs must present expert testimony demonstrating that exposure to breast implants more than doubled the risk of their alleged injuries. Hall, 947 F.Supp. at 1403 (citing Daubert, 43 F.3d at 1320); Sanderson v. International Flavors and Fragrances, Inc., 950 F.Supp. 981, 1004 (C.D.Cal.1996) (excluding causation evidence as irrelevant under Daubert where experts did not opine that exposure “more than doubled” the risk of injury) (citing Daubert, 43 F.3d at 1320-22). If exposure to breast implants does not at least double the risk of injury, then more than half of the population suffering from the injuries allegedly caused by breast implants would be injured anyway (the background rate of injury), thereby disproving legal causation. Hall, 947 F.Supp. at 1398; see also Daubert, 43 F.3d at 1321 (“[a] relative risk of less than two may suggest teratogenicity, but it actually tends to disprove legal causation, as it shows that Bendectin does not double the likelihood of birth defects”). Under Colorado law, testimony about medical causation is only relevant if it allows a juiy to find that it is more likely than not that the conduct of the defendant was a substantial factor in the plaintiffs’ injury; in other words, causation must be proven within reasonable probability. Kaiser Foundation Health Plan of Colo. v. Sharp, 741 P.2d 714, 719 (Colo.1987) (jury may decide causation “as long as the evidence establishes such facts and circumstances as would indicate with reasonable probability that causation exists”). This means that Plaintiffs must present expert testimony demonstrating that exposure to breast implants more than doubled the risk of their alleged injuries. Sharp v. Kaiser Foundation Health Plan of Colo., 710 P.2d 1153, 1155 (Colo.App.1985) (plaintiff met standard of proof that defendant “substantially increased plaintiffs risk” since plaintiffs “chances of a heart attack, under this evidence, was more than doubled”), aff'd, 741 P.2d 714 (Colo.1987). In Colorado, a plaintiff seeking to prove causation must demonstrate that her injuries were “more likely than not” caused by exposure to defendant’s product. Kaiser, 710 P.2d at 1155. In applying the Daubert criteria, “[t]his burden requires Plaintiffs to demonstrate that exposure to breast implants more than doubled the risk of their alleged injuries.” Hall, 947 F.Supp. at 1403 (citing Daubert, 43 F.3d at 1320). In terms of epidemiology, this means that the relative risk must be statistically significant. The difference between groups is often expressed as the ratio between the incidence of the disease in the exposed group and the incidence in the unexposed group. Marcia Angelí, M.D., SCIENCE ON TRIAL (1996) at 164. The relative risk simply indicates how high above the background level the risk is. The threshold for concluding that an agent was more likely the cause of a disease than not is a relative risk greater than 2.0. Recall that a relative risk of 1.0 means that the agent has no effect on the incidence of disease. When the relative risk reaches 2.0, the agent is responsible for an equal number of cases of disease as all other background causes. Thus, a relative risk of 2.0 implies a 50% likelihood that an exposed individual’s disease was caused by the agent. Hall, 947 F.Supp. at 1403 (quoting REFERENCE MANUAL ON SCIENTIFIC EVIDENCE at 168). For example, if the relative risk for a disease between women with breast implants and women without breast implants is 1.2, it means that for every 10 women without implants who develop the disease, 12 women with implants in an equal population would develop the disease. SCIENCE ON TRIAL at 196. It is important to realize that we do not know exactly what a relative risk of 1.2 means for each of those 12 women who develop connective tissue disease. It could mean that in 2 of them, the implants were the sole cause of their disease and in the other 10 they played no role. Or it could mean that implants played a major role in 3 or 4 women and a very small one in the others. Or it could mean that implants contributed a varying amount to the disease in all 12.... All we could say for sure with a relative risk of 1.2 is that on average, implants contributed about 17 percent (0.2/1 .2) to the disease. For any one woman among the 12, then, we could not say that but for the implants, she would not have developed the disease. Further, we would have to say that some other factor or group of factors was the dominant cause. SCIENCE ON TRIAL at 196-97 (emphasis in original). D. The Epidemiological Evidence Demonstrates the Absence of a Doubling of the Risk At least seventeen epidemiological studies of breast implants have been published in peer reviewed medical journals. (Ory Affidavit ¶¶ 35, 36). Every controlled epidemiological study concludes that silicone breast implants do not double the risk of any known disease. See Affidavits of Dr. Ory, M.D., Dr. Schlesselman, M.D., Dr. Felson, M.D., Dr. Layde, M.D., Dr. Marcus, M .D., Dr. Rose, M.D., Ph.D., Dr. Jones, M.D., and Dr. Steen, M.D., Exhibits A through H to Defendants’ Science Brief. None of these studies support a conclusion that breast implants cause rheumatic or connective tissue diseases, either classic or atypical, in breast implanted women. Id. None of these studies reports a statistically significant elevation of risk of rheumatic or connective tissue disease, either classic or atypical, over 2.0. Id. The reported results from every published controlled epidemiological study uniformly show the absence of a doubling of the risk of any known disease among breast implant recipients. Hall, 947 F.Supp. at 1405 (“none of the 16 epidemiological studies found that women with silicone breast implants faced a relative risk of classical disease or disease signs and symptoms of anywhere near 2.0”). As a whole, these studies provide a solid body of epidemiologic evidence establishing that breast implants do not cause connective tissue disease, autoimmune disease or various symptoms. Specifically, in June 1994, the New England Journal of Medicine published a large, rigorous, and well controlled epidemiological study conducted by the Mayo Clinic, which explored the hypothesized link between implants and connective-tissue and other diseases. Gabriel, et al., “Risk of Connective-tissue Diseases and Other Disorders After Breast Implantation,” 330 N. ENGL. J. MED. 1697 (1994) (“the Mayo Clinic Study”). The Mayo Clinic Study failed to, find an association between implant history and various connective-tissue diseases and symptoms thereof, such as those alleged by plaintiffs. Rather, the Mayo Clinic Study found that women with implants had no greater incidence of connective tissue or autoimmune disorders than women without implants. The largest study to date concluded that there is no doubling of the risk of connective tissue disease among women with breast implants. Hennekens, et al., “Self-Reported Breast Implants and Connective-Tissue Diseases in Female Health Professionals,” 275 J. AM. MED. ASSOC. 616 (February 28,1996) (“Hennekens Study”). The Hennekens Study included almost 400,000 female health professionals who completed mailed questionnaires, including more than 10,000 who reported having breast implants and almost 12,000 who reported having connective-tissue diseases between 1962 and 1991. Id. The relative risk for all connective-tissue diseases was estimated at 1.24 (95% confidence interval, 1.08 to 1.41). Id. As the authors themselves noted, this study suffered from bias which probably explains the slight increased relative risk. Id. Furthermore, the Kelley court summarized some of the limitations of this study: “[f]or the Hennekens study, the strength of association is low, the consistency of the association is also low (i.e., the study suggested that more tests were necessary before meaningful conclusions could be draw), alternative explanations are likely, the association is not specific, and there is no dose-response relationship.” 957 F.Supp. at 879 (citing the Hennekens Study). As the court explained in Hall, the Hennekens Study, in which the relative risk was “only 1.24, ... cannot support expert testimony that silicone ‘more likely than not’ causes disease or signs and symptoms of disease in women.” 947 F.Supp. at 1405. A definition for a new atypical syndrome associated with silicone gel breast implants has not been set forth in the published medical literature, nor has it been defined by Plaintiffs’ designated experts. A disease entity lacking definition cannot very well be examined in a controlled epidemiologic study. To the extent that there are case or anecdotal reports noting various symptoms or signs in breast implanted women, without controls, these suggest only a potential, untested hypothesis that breast implants may be their cause. Such case reports are not reliable scientific evidence of causation, because they simply describe reported phenomena without comparison to the'rate at which the phenomena occur in the general population or in a defined control group ... [T]hey do not isolate and exclude potentially alternative causes ... and do not investigate or explain the mechanism of causation. Casey v. Ohio Medical Products, 877 F.Supp. 1380, 1385 (N.D.Cal.1995). An untested hypothesis cannot be a scientifically reliable basis for an opinion on causation. In the absence of a defined new atypical syndrome associated with silicone gel breast implants, a number of controlled epidemio-logic studies have nonetheless examined the question of whether an atypical syndrome is associated with silicone gel breast implants. In a recent study conducted at the Harvard Medical School, involving 87,501 nurses, 1183 of whom had implants, the authors noted that “[w]e studied women with possible early milder or atypical forms of connective-tissue disease or with any sign or symptom of a connective-tissue disease who did not meet standard classification criteria.” Sanchez-Guerrero et ah, “Silicone Breast Implants and the Risk of Connective-Tissue Diseases and Symptoms,” 332 N. Engl. J. Med. 1666, 1668 (1995) (“the Harvard Nurses Study”). In conclusion, the Harvard Nurses Study authors found no statistically significant association between breast implants and atypical presentation of connective tissue disease or classic connective tissue disease. Also notable is the consistency of the epidemiological studies. All of the significant epidemiological studies have failed to find a doubling of the relative risk. Consistency of findings is used not only by epidemiologists but all scientists as an important factor in assessing cause and effect. The consistent absence of an elevated relative risk weighs against any materially increased risk of disease caused by silicone gel breast implants. E. Plaintiffs’ Causation Evidence Is Not Scientifically Reliable To prove causation, Plaintiffs Zelinger and Roberts offer the testimony of rheu-matologist Dr. Kassan, neurologist Dr. Klap-per, neuropsychiatrist Dr. Hoffman, and biomaterials scientists, Dr. Guidoin and Dr. Blais. No Plaintiffs’ expert witness report states an opinion on general causation; the physician witnesses offer only specific causation opinions and the non-physician witnesses purportedly do not offer opinions about causation. The reports submitted by Plaintiffs’ experts fail to present a single peer-reviewed, controlled epidemiologic study that support their causation theories. This is not to say that epidemiological studies are required in this type of tort action. Epidemiological studies are not the magical cure for legal disputes. In many instances, epidemiological data may be unavailable. A lack of epidemiology should not end the inquiry, but rather begin the inquiry into what other types of evidence a plaintiff can present to satisfy the burden of proof. There is a range of scientific methods for investigating questions of causation, for example, toxicology and animal studies, clinical research, and epidemiology, all of which have distinct advantages and disadvantages. The court’s inquiry is whether reliable scientific evidence, based on sound methodology, has been presented. What is significant in this case is that the substantial body of epidemiological evidence demonstrates that silicone breast implants do not double the risk of any known disease. Plaintiffs’ expert witnesses Drs. Kassan and Klapper identified only three specific medical publications in support of their opinions. Dr. Kassan cites Hennekens, supra, and Silverman et al., “Reported Complications of Silicone Gel Breast Implants: An Epidemiologic Review,” 124 Annals of Internal Med. 744 (April 15, 1996). Dr. Klapper cites Greenland et ah, “A Case Control Study of Prosthetic Implants and Selected Chronic Diseases,” Annals of Epidemiology 6:530-540 1996. None of the other Plaintiffs’ experts specifically rely on any literature at all regarding causation. As discussed above, the Hennekens study cited by Dr. Kassan demonstrated a modest increase in a relative risk of 1.24. It does not establish that breast implants more probably than not cause disease, and its findings are contrary to the other epidemiological studies which consistently demonstrate no increased relative risk. The Silverman article cited by Dr. Kassan is merely a review by the U.S. Food and Drug Administration (“FDA”) of the epidemiologic literature, containing no original data. Athough the article addresses the shortcomings of the epidemiology from a regulatory perspective (i.e. the epidemiology does not conclusively demonstrate safety), the relevant inquiry here is whether breast implants substantially increase (i.e.double) the risk of any known disease. Indeed, even the FDA acknowledges that “taken together, these studies suggest no substantial increase in the risk for scleroderma or other well-defined connective tissue diseases overall as a result of breast implantation.” Id. at 751. The Greenland article cited by Dr. Klapper does not involve breast implants. In fact, the authors note with regard to breast implants that: “[ejlaims of such [systemic effects] have resulted in successful litigation against implant manufacturers, despite the fact that epidemiologic studies to date have not detected an association between implants and long-term health effects.” Annals of Epidemiology 6:530. The authors also stated as to their data on bone, joint, testicular and penile implants: “[gjiven the limitations of our data, we cannot reach any firm conclusions regarding implant effects.” Id. at 539. Plaintiffs cite Hennekens, Silverman and Greenland, but point to no peer-reviewed epidemiological studies that support their causation theories. Their theories cannot, therefore, suffice as evidence because, as the Fifth Circuit stated in Brock, theories of toxic causation “unconfirmed by epidemiologic proof cannot form the basis for causation in a court of law.” 874 F.2d at 315. Based on the conclusions reached in Hennekens, Silverman and Greenland, the court finds it unreasonable for Plaintiffs’ experts to rely on these three studies to conclude that a causal relationship existed between silicone gel breast implants and the diseases and symptoms from which Plaintiffs allegedly suffer. Kelley, 957 F.Supp. at 878; Hall, 947 F.Supp. at 1403-1407; In re Breast Implant Cases, 942 F.Supp. at 961. 1. Differential Diagnosis Plaintiffs seek to introduce expert testimony from clinicians (i.e., treating physicians) who claim to be able to diagnose a patient with a disease caused by breast implants through the process of differential diagnosis. Drs. Klapper and Kassan have provided written opinions which state that they, as treating physicians of the Plaintiffs, have used the medical procedure of differential diagnosis and have determined to “a reasonable degree of medical certainty” that the illnesses and symptoms from which the Plaintiffs suffer are caused by the silicone from their silicone gel breast implants. Such testimony is not scientifically rehable in the cases before the court because it confuses two distinct burdens. Plaintiffs must demonstrate two types of causation: general causation and specific causation. Raynor, 104 F.3d at 1376; Kelley, 957 F.Supp. at 875 (citations omitted); Hall, 947 F.Supp. at 1412-1413 (citations omitted); Rutigliano, 929 F.Supp. at 783; In re Silicone Gel Breast Implants Products Liability Litig., 887 F.Supp. at 1477. By using differential diagnosis, a clinician can identify possible diseases the patient may have and, through a process of elimination, rule out diseases until a disease or symptom is left as the diagnosis. Differential diagnosis is not a scientific method by which a physician can determine whether silicone breast implants can cause disease in humans. As the court explained in Hall, [differential diagnosis is a patient-specific process of elimination that medical practitioners use to identify the ‘most likely’ cause of a set of signs and symptoms from a list of possible causes. However, differential diagnosis does not by itself prove the cause, even for the particular patient. Nor can the; technique speak to the issue of general causation. Indeed, differential diagnosis assumes that general causation has been proven for the list of possible causes it eliminates: The process of differential diagnosis is undoubtedly important to the question of “specific causation.” If other possible causes of an injury cannot be ruled out, or at least the probability of their contribution to causation minimized, then the “more likely than not” threshold for ' proving causation may not be met. But, it is also important to recognize that a fundamental assumption underlying this method is that the final, suspected “cause” remaining after this process of elimination must actually he capable of causing the injury. That is, the expert must “rule in” the suspected cause as well as “rule out” other possible causes. And, of course, expert opinion on this issue of “general causation” must be derived from a scientifically valid methodology. 947 F.Supp. at 1413 (emphasis in original) (quoting Cavallo v. Star Enterprise, 892 F.Supp. 756, 771 (E.D.Va.1995), aff'd on this ground, rev’d on other grounds, 100 F.3d 1150 (4th Cir.1996), cert. denied, 118 S.Ct. 684, 118 S.Ct. 684, 139 L.Ed.2d 631 (1998)). As a practical matter, the cause of many diseases remains unknown; therefore, a clinician who suspects that a substance causes a disease in some patients very well might conclude that the substance.caused the disease in the plaintiff simply because the clinician has no other explanation. See Margaret A. Berger, “Evidentiary Framework,” REFERENCE MANUAL ON SCIENTIFIC EVIDENCE at 81 (1994). The kind of causation testimony offered by Plaintiffs’ experts was summarized and rejected by Judge Prado in Kelley: [T]he witness admits that if the Plaintiff did not have breast implants but had the exact same symptoms and blood chemistry, then his diagnosis would have been non-implant-caused Sjogren’s Syndrome. Essentially, this is a bit like saying that if a person has a scratchy throat, runny nose, and a nasty cough, that person has a cold; if, on the other-hand, that person has a scratchy throat, runny nose, nasty cough, and wears a watch, they have a watch-induced cold. Such reasoning is extremely suspect, which has prompted other courts to reject it as unscientific in the absence of convincing epidemiology evidence. 957 F.Supp. at 882 (citing Brock, 874 F.2d at 310 n. 11). The causation testimony offered by the Plaintiffs is precisely the kind of subjective testimony that is inadmissible pursuant to Rules 702 and 703. “Reasoning that a cause-and-effect relationship exists simply because a large number of individuals with a particular characteristic develop a particular disease is fallacious, because it totally fails to account for the fact that both characteristics and diseases are widely distributed among the general population.” (Ory Affidavit ¶ 50). In short, “a single differential diagnosis is a scientifically invalid methodology” for the purpose of demonstrating general causation. Hall, 947 F.Supp. at 1414. Differential diagnosis may be utilized by a clinician to determine what recognized disease or symptom the patient has, but it is incapable of determining whether exposure to a substance caused disease in the legal sense. 2. Plaintiffs’ Experts’ Clinical Experience Insufficient for General Causation Opinion Plaintiffs’ experts rely on their individual clinical experience of seeing many patients with silicone breast implants and their review of the medical literature to opine that silicone breast implants cause disease. Such experience is the equivalent or a series of case reports, or observations made about a particular patient. Case reports can give rise to a question about causation; epidemiology answers the question: [T]he generally accepted view in the scientific community is that her methodology [case reports and animal studies] can be used to generate hypotheses about causation, but not causation conclusions. [Scientifically valid cause and effect determinations depend on controlled clinical trials and epidemiological studies ... Haggerty v. Upjohn Co., 950 F.Supp. 1160, 1164 (S.D.Fla.1996) (excluding causation evidence as scientifically unreliable and irrelevant pursuant to Daubert). As explained in Hall, “case reports, and case studies universally are regarded as an insufficient scientific basis for a conclusion regarding causation because case reports lack controls.” 947 F.Supp. at 1411 (citations omitted). Courts have rejected case reports as unreliable: Such ease reports are not reliable scientific evidence of causation, because they simply described reported phenomena without comparison to the rate at which the phenomena occur in the general population or in a defined control group; do not isolate and exclude potentially alternative causes; and do not investigate or explain the mechanism of causation. Even if some credibility were given to the study, it does not have the degree of clarity required for a validation of its results or its methodology which is sufficient for objective and independent peer review. Casey, 877 F.Supp. at 1385; Jones, 933 F.Supp. at 898 (“[plaintiffs’ evidence falls far short of the proven cause and effect relationship that is necessary to satisfy the Daubert standard”); Muzzey v. Kerr-McGee Chemical Corp., 921 F.Supp. 511, 519 (N.D.Ill.1996) (“[ajneedotal reports ... are not reliable bases to form a scientific opinion about a causal link”) (citing REFERENCE MANUAL ON SCIENTIFIC EVIDENCE at 344 n. 25 (1994)). 3. Plaintiffs’ Studies and Articles Plaintiffs’ have submitted 40 epidemiology studies, 40 immunology studies, 40 rheumatology studies, 40 toxicology studies, and 100 “general articles” regarding various scientific studies. The Plaintiffs’ submissions are essentially identical to those submitted to the 706 panel convened by Judge Pointer in the multi-district litigation in the District of Alabama. None of the Plaintiffs’ expert witness reports referred to any of these additional studies or articles; therefore, those materials cannot properly be considered as additional support for the witnesses’ methodology or conclusions. Nevertheless, the court has examined the numerous studies and articles and determines that they do not reasonably support the conclusions of the Plaintiffs’ expert witnesses. Many of the studies and articles submitted by Plaintiffs were inconclusive, merely recommending that further studies be done. Some studies were, at best, remotely related to breast implants; for example, studies of occupational exposure to inhaled crystalline silica, such as asbestos, silica dust, quartz dust, and granite dust, and studies of the use of silicone oil in vitreoretinal surgery. See Jones Affidavit, Exhibit G to Defendants’ Science Brief. A sampling of the studies and articles suffices to illustrate that these materials as a whole do not support the Plaintiffs’ experts’ conclusions regarding causation: Bar-Meir, E., et al, “Multiple Autoantibodies in Patients with Silicone Breast Implants,” Journal of Autoimmunity, 8:267-77 (1/1/95) (“[t]he question why some women develop autoantibodies following exposure to silicone, or even overt autoimmune disease, is unresolved”); Claman, Henry, M.D. and Robertson, Alastair D., Ph. D., “Antinuclear Antibodies and Breast Implants,” Western Journal of Medicine, 160(3): 225-28 (3/1/94) (“larger and more carefully executed analytical studies are needed to test -the hypothesis that a relationship exists between breast implants and autoimmunity”); Giltay, Erik J., et al, “Silicone Breast Prostheses and Rheumatic Symptoms: a Retrospective Follow Up Study,” Annals of Rheumatic Disease, 53:194-96 (1/1/94) (“we conclude that common and clinically manifest rheumatic diseases do not occur more frequently among women with silicone breast prostheses”); Granchi, Donatella, et al., “Silicone Breast Implants: The Role of Immune System on Capsular Contracture Formation,” Journal of Biomedical Materials Research, 29(2):197-202 (2/1/95) (“our data suggest the hypothesis of an involvement of the immune system in the formation of an excess of fibrous tissue responsible for a severe capsule contracture ... ”); Kossovsky, Nir, et al., “Surface Dependent Antigens Identified by High Binding Avidity of Serum Antibodies in a Subpopulation of Patients with Breast Prostheses,” Journal of Applied Biomateri-als, 4:281-188 (12/1/93) (“[t]he long-term biological and clinical consequences of the presence of these antibodies remains to be assessed”); Naim, J.O., et al., “The Induction of Type II Collagen Arthritis in the DA Rat Using Silicone Gel as Adjuvant,” Current Topics in Microbiology and Immunology — Immunology of Silicones, 210:103-11 (1/1/96) (“silicone gel alone does not appear to be arthritogenic.”); Wells, Karen E., M.D., et al., “The Health Status of Women Following Cosmetic Surgery,” Plastic and Reconstructive Surgery, 93(5):907-12 (4/1/94) (“no cases of scleroderma or lupus were found, and the incidence of arthritis was not significantly different between the implant and control groups”); Young, Y. Leroy, M.D., et al, “HLA Typing in Women with Breast Implants,” Plastic and Reconstructive Surgery, 96(7): 1197-1519 (12/1/95) (“[s]erologic testing, rheumatologic evaluations, and epidemiologic studies have failed to demonstrate an etiologic connection between silicone gel breast implants and any recognized connective-tissue disease in women who have undergone breast reconstruction or augmentation mammaplasty ... Thus far all the research into the question of what is happening with symptomatic breast implant patients has produced no conclusive proof that these women are experiencing any kind of immunologic response to their implanted devices”); McDonald, A.H., et al., “Silicone Gel Enhances Autoimmunity in NZB Mice but Fails to Induce Disease in B ALB/C Mice,” Journal of Allergy and Clinical Immunology 99(1): S195 (Abstract 785) (“[tjhus, our results are consistent with several epidemiological studies demonstrating no increase in the incidence of autoimmune disease in women with breast implants”). 4. Temporality Plaintiffs’ experts assert that causation may be inferred based upon the temporal sequence of implantation and the onset of illness. A temporal relationship by itself, provides no evidence of causation. In re Swine Flu Immunization Products Liability Litig., 533 F.Supp. 567 (D.Colo.1980); Willert v. Ortho Pharmaceutical Corp., 995 F.Supp. 979 (D.Minn. 1998) (citing Sorensen v. Shaklee Corp., 31 F.3d 638, 649 (8th Cir.1994)). Temporality at best addresses the issue of specific causation; therefore, evidence of temporality is inadmissible where no admissible evidence of general causation exists. Kelley, 957 F.Supp. at 882 (“[i]n the absence of any evidence regarding general causation, the Court will not permit Dr. Espinoza to testify as to specific causation”) (citations omitted); Hall, 947 F.Supp. at 1413 (“[testimony regarding specific causation in a given patient is irrelevant unless general causation is established”) (citations omitted). Even as to specific causation, temporality cannot withstand Daubert scrutiny. See Cuevas v. DuPont, 956 F.Supp. 1306, 1307-09 (S.D.Miss.1997) (excluding causation evidence based on the temporal relationship between exposure and medical problems); Sanderson, 950 F.Supp. at 988, 995-96, 1004 (excluding causation evidence consisting primarily of temporal relationship between exposure and onset of symptoms); Cartwright v. Home Depot USA, Inc., 936 F.Supp. 900 (N.D.Fla.1996) (excluding expert testimony where causation opinion of expert witness was based solely on temporal relationship); Cavallo v. Star Enterprise, 892 F.Supp. at 773 (a causation opinion based solely on a temporal relationship is not derived from the scientific method and is therefore insufficient to satisfy the requirements of Rule 702) (citing Schmaltz v. Norfolk & Western Ry. Co., 878 F.Supp. 1119, 1122 (N.D.Ill.1995)); In re Swine Flu Immunization Products Liability Lit., 533 F.Supp. at 572 (mere temporal relation is insufficient to establish legal causation). F. Stuart Kassan, M.D. Plaintiffs’ rheumatology expert, Stuart Kassan, M.D., is board-certified by the American College of Rheumatology (ACR). If permitted, Dr. Kassan would testify that as to Plaintiffs Zelinger and Roberts: it is my medical opinion to a reasonable degree of medical certainty that the silicone gel breast implants to which this patient was exposed caused many of her above described symptoms and illnesses. (Kassan’s reports, Exhibit 5 to Plaintiffs’ July 15, 1997 Opposition to Defendants’ Science Brief). Dr. Kassan limits his opinion to specific causation — he will not testify that silicone breast implants cause disease in people in general. (Kassan Deposition, April 15, 1998 pp. 78-79). The Plaintiffs’ symptoms and “problems” vary widely, and include Sjo-gren’s syndrome, peripheral neuropathy, Raynaud’s phenomenon, CREST syndrome, and fibromyalgia. As a basis for his opinion Dr. Kassan states as to each Plaintiff that “this patient has been exposed to silicone from her breast implants which may have stimulated the immune system causing the disease process.” He opines that “there is a basis in the literature to suggest that silicone is related to autoimmune disease,” citing JAMA, February 28, 1996 Vol. 275, No. 8 (“Hennekens study”); Annals of Internal Medicine, April 15, 1996, Vol. 124, No. 8 (“Silverman study”); and unidentified abstracts and publications from Arthritis and Rheumatism, 1994,1995, and 1996. However, Dr. Kassan recently stated that he is not relying on any published medical literature. (Kassan Deposition pp. 130-31). First, a suggestion or possibility of a relationship is insufficient for a causation opinion under Colorado law, the Federal Rules of Evidence, and Daubert, 509 U.S. at 579, 113 S.Ct. 2786. Songer v. Bowman, 804 P.2d 261, 265 (Colo.App.1990), aff'd 820 P.2d 1110 (Colo.1991); Kaiser v. Sharp, 741 P.2d at 719. The cited articles do not state or otherwise support the conclusion that silicone breast implants can cause systemic disease, and are not a reliable basis for the conclusion reached by Dr. Kassan. Second, the specific causation evidence offered by Dr. Kassan is non-epidemiological in nature. In the face of numerous epidemiological studies, Dr. Kassan relies on his clinical experience, differential diagnosis, and his review of the medical literature to conclude that the Plaintiffs’ described symptoms and problems are caused by their exposure to silicone gel breast implants. Plaintiffs have provided no validation of Dr. Kassan’s methodology as being generally accepted in the medical community or reasonably relied upon by other rheumatologists in reaching an opinion on causation. The rheumatology community looks to controlled studies (epidemiology) and the Bradford Hill criteria to determine cause of diseases. Reliance on clinical experience, case reports and other anecdotal evidence has been rejected by the American College of Rheumatology as a basis for opinions on causation. See American College of Rheumatology, “Statement on Silicone Breast Implants,” October 1995 (“[t]he American College of Rheumatology believes that these studies provide compelling evidence that silicone implants expose patients to no demonstrable additional risk for connective tissue or rheumatic disease. Anecdotal evidence should no longer be used to support this .relationship in the courts ... ”), and “Updated Silicone Breast Implants Statement” (10/22/95) (“[t]o date, there continues to be no clear and consistent association of a defined connective tissue disease with silicone breast implants”); European Committee on Quality Assurance and Medical Devices in Plastic Surgery, “Consensus Declaration EQUAM”, June 28, 1996 (“[tjhere is conclusive scientific — clinical, immunological, epidemiological — proof, that silicone breast implants do not cause identified and recognised [sic] auto-immune diseases nor connective tissue diseases such as rheumatoid arthritis, scleroderma, systemic lupus erythematosus. There is no consistent evidence, that implants are responsible for undefined connective tissue diseases”); National Multiple Sclerosis Society, “Silicone Breast Implants and Multiple Sclerosis-Like Disorder,” May 13,1994 (“[i]t is important to note that there are no valid scientific data indicating that silicone implants are related to the onset of typical multiple sclerosis”); and the epidemiology discussed at part II. C. of this memorandum opinion and order, sit- pm. Dr. Kassan acknowledges that “[t]here have been no definitive studies on the relationship between atypical disease, such- as the one which this patient suffers from, and silicone.” (Kassan’s reports). Dr. Kassan’s failure to utilize the epidemiology in forming his opinion has not been explained. Plaintiffs claim that Dr. Kassan relied on differential diagnosis to rule out causes other than silicone for plaintiffs’ complaints and symptoms. However, Dr. Kassan does not explain what alternative causes he considered, or how he ruled out other possible causes. Dr. Kassan admits that “many of my patients with symptoms such as these do not have breast implants.” As discussed in part II.D.l. of this memorandum opinion and order, supra., differential diagnosis is not a means to determine whether an exposure to a chemical can cause disease. Dr. Kassan offers no tested or testable theory to explain how, from his limited information, he was able to eliminate all other potential pauses of Plaintiffs Zelinger’s and Roberts’ conditions, nor does he explain how he alone can state as a fact that the Plaintiffs’ breast implants caused their “problems.” A statement does not become scientific knowledge because it is uttered by a doctor. Nor can an expert witness’ self-serving assertion that his conclusions were derived by a scientific method be deemed conclusive. Joiner, 118 S.Ct. at 518-19 (“[b]ut nothing in either Daubert or the Federal Rules of Evidence requires a district court to admit opinion evidence which is connected to existing data only the ipse dixit of the expert”); Daubert, 43 F.3d at 1316 (to demonstrate the reliability of proffered scientific evidence, “an expert’s bald assurance of validity is not enough”); Viterbo, 826 F.2d at 424 (when the expert brings “to court little more than his credentials and a subjective opinion,” this is not evidence that would support a judgment and it offers no expert assistance to the jury); Grimes v. Hoffmann-LaRoche, Inc., 907 F.Supp. 33, 38 (D.N.H. 1995) (“an expert cannot establish that a fact is generally accepted merely by saying so”). Dr. Kassan’s conelusory statement that he has ruled out other causes for the Plaintiffs’ symptoms is not supported by any meaningful information about how he was able to exclude the many possible alternative causes of the problems alleged by the Plaintiffs. Stover v. Eagle Products, Inc., 1996 WL 172972 *11 (D.Kan.1996) (“[a]n explanation for discounting those alternative causes is critical to evaluating the methodology used in reaching his conclusion. Yet, based on the information apparently relied on ... and the conelusory nature of his opinion, it is impossible to discern any manner by which the alternative causes were excluded.”) Dr. Kassan relies on his observations of the women he has treated in his clinical practice. These observations are in the nature of case reports or case studies. (Ory Affidavit ¶ 53). Dr. Kassan has not developed appropriate control groups (women without breast implants) with which to compare the women in his practice. Id. Dr. Kassan acknowledges that many of his patients with similar symptoms do not have breast implants. He admits that he has not identified a difference between his patients with Sjogren’s syndrome or lupus-like phenomena and breast implants and his patients with Sjogren’s syndrome or lupus-like phenomena who do not have breast implants. (Kassan Deposition pp. 61-62). The evidence indicates that many of Dr. Kassan’s patients are litigants who have been referred to him. These facts contribute to a high rate of error for his hypothesis. The relatively small size of Dr. Kassan’s sample of women with breast implants also indicates that it is not reasonably relied upon to form his conclusion that the Plaintiffs’ breast implants caused their symptoms. Dr. Kassan has' performed no testing of his hypothesis that silicone breast implants caused atypical rheumatic disease in the Plaintiffs. ACTD is not defined and is at best an untested hypothesis. Without an accepted disease definition for ACTD, it cannot be tested scientifically, yet some epidemiological studies looked at atypical presentations and symptoms of rheumatic disease and found valid no association, i.e., “the Harvard Nurses Study”. Dr. Kassan has not published any of the theories he has proffered in any peer-reviewed journal. Dr. Kassan has not subjected his methodology of determining causation by clinical experience and differential diagnosis to peer-review. Peer review and publication weigh heavily in determining the reliability of expert testimony because such review “increases the likelihood that substantive flaws in methodology will be detected.” Daubert, 509 U.S. at 593, 113 S.Ct. 2786. The epidemiology studies relied on by Defendants have been printed in peer-reviewed publications and subjected to close scrutiny by the scientific and/or medical community. Dr. Kassan’s non-epidemiological methodology, including reliance on anecdotal case reports and theories about the mechanism by which breast implants might cause disease, is not sufficient to support his conclusions that are directly contrary to the epidemiology. Dr. Kassan’s non-epidemiological methodology has not been objectively tested, has no known rate of error, and is not generally accepted by the medical community as validation that silicone gel breast implants caused the Plaintiffs’ various conditions and symptoms. When a scientist claims to rely on a method practiced by most scientists, yet presents conclusions that are shared by no other scientist, the district court should be wary that the method has not been faithfully applied. It is the proponent of the expert who has the burden of proving admissibility. To enforce this burden, the district court can exclude the opinion if the expert fails to identify and defend the reasons that his conclusions are anomalous. Lust v. Merrell Dow Pharmaceuticals, Inc., 89 F.3d 594, 598 (9th Cir.1996). The substantial body of epidemiology renders Dr. Kassan’s non-epidemiological evidence scientifically