Civil Litigation
Jul. 3, 2001
Tough Standard
'Glastetter' demonstrates just how rigorous an analysis must be employed by federal judges evaluating causation issues in tort cases.
David E. Stanley
Reed Smith
355 S Grand Ave #2900
Los Angeles , CA 90071
Phone: (213) 457-8000
Email: dstanley@reedsmith.com
Pepperdine Law School
David J. de Jesus
Counsel, Reed Smith LLP
101 2nd St Ste 1800
San Francisco , CA 94105
Phone: (415) 543-8700
Fax: (415) 391-8269
Email: ddejesus@reedsmith.com
Loyola Law School; Los Angeles CA
David is in the firm's Appellate Group, resident in San Francisco office. He is certified as specialists in appellate law by the California State Bar Board of Legal Specialization.
When the U.S. Supreme Court issued Daubert v. Merrell Dow Pharmaceuticals Inc., 509 U.S. 579 (1993), the seminal federal case on the admissibility of scientific evidence, many commentators contended that more expert opinions would be admitted. The Daubert standard, they said, was more flexible and thus presumably more lenient, than the traditional test of the admissibility of expert testimony first set forth in Frye v. United States, 293 F. 1013 (D.C. App. 1923).
California, which follows this traditional test, allows expert testimony only where the opinion derives from a practice "generally accepted" by the relevant expert community. See, e.g., People v. Leahy, 8 Cal.4th 587 (1994); People v. Kelly, 17 Cal.3d 24 (1976).
Time has shown, however, that Daubert's mandate requiring the courts to act as gatekeepers to ensure that every expert opinion is supported by a scientifically valid foundation has proved far more important. See, e.g., "Reference Manual On Scientific Evidence" (Fed. Judicial Ctr. 2d ed. 2000).
As the federal courts have taken up that charge, they have had to develop ever-greater sophistication in many areas of science and medicine and to display the depth of that expertise in published opinions. A recent case from the 8th U.S. Circuit Court of Appeals, Glastetter v. Novartis Pharmaceuticals Corp., 630651 (8th Cir. June 8, 2001), demonstrates just how rigorous an analysis must be employed by federal judges evaluating causation issues in tort cases.
In Glastetter, the plaintiff was a woman who chose not to breast-feed her baby. To suppress postpartum lactation, Tina M. Glastetter's doctor prescribed Parlodel, a drug approved for that purpose. Two weeks later, the plaintiff suffered an intracerebral hemorrhage - a stroke - in the right side of her brain, which resulted in left-side paralysis and slurred speech.
Though her doctors were unable to pinpoint the source of the stroke, Glastetter believed that Parlodel was the cause and sued the manufacturer in federal court under state law product-liability theories.
Parlodel was not a new drug when Glastetter took it. It had Food and Drug Administration approval and had been on the market for almost 20 years. However, six months after the plaintiff suffered her stroke, the FDA withdrew its earlier approval, claiming that the drug's potential harm - including the possibility of strokes in select groups of women - outweighed the benefits of suppressing lactation.
During discovery, Glastetter retained two qualified experts to testify regarding the medical cause of her stroke. Both experts theorized that Parlodel caused Glastetter's arteries to constrict ("vasoconstriction"), resulting in elevated blood-pressure levels. Because high blood pressure is a known risk for stroke, the experts concluded that Parlodel caused Glastetter's stroke.
The experts based their vasoconstriction theory on several types of scientific data, including differential diagnoses, case studies, human rechallenge-dechallenge data and the FDA's revocation of its approval for Parlodel.
Parlodel's manufacturer, however, raised a Daubert challenge to these experts' opinions, arguing that the data on which they were based lacked scientific reliability. After a four-day evidentiary hearing, the District Court agreed and excluded the opinions of both experts. See Glastetter v. Novartis Pharm. Corp., 107 F. Supp.2d 1015 (E.D. Mo. 2000). The ruling gutted Glastetter's claims and allowed the defendant to successfully move for summary judgment.
The 8th Circuit affirmed, and its review of the scientific reliability of plaintiffs' experts opinions explores each of the different types of scientific data. The value of Glastetter lies in its situational application of Daubert to a variety of scientific data that often confronts litigants in pharmaceutical and medical-device litigation. For each type of scientific data, the court applied Daubert to hold that the data was scientifically unreliable and, therefore, inadmissible.
• Differential-diagnosis methodology. A differential diagnosis takes a reverse approach to diagnosing patients. A treating physician conducts a differential diagnosis by initially "ruling in" all scientifically plausible causes for the patient's symptoms. Based on further examination and testing, the physician then "rules out" each less-plausible cause until the most likely cause of the symptom remains. Both of Glastetter's experts used this approach.
The 8th Circuit did not question the general validity and utility of this method but concluded that it was inadmissible because Glastetter's experts lacked a critical piece of preliminary evidence: epidemiological studies demonstrating that Parlodel was a possible cause of stroke in the first place and was added properly to the list of all possible causes of stroke. Without such a foundational showing, the differential-diagnosis method failed to pass the Daubert standard for scientific reliability.
• Case studies. Glastetter's experts relied heavily on case studies from doctors who reported patient strokes following ingestion of Parlodel. However, the District Court cited a significant body of authority casting doubt on the reliability of often-unproved and isolated case reports as a basis for a medical causation opinion. See, e.g., Allison v. McGhan Med. Corp., 184 F.3d 1300 (11th Cir. 1999); Hollander v. Sandoz Pharms. Corp., 95 F. Supp. 1230 (W.D. Okla. 2000); Pick v. American Med. Sys., 958 F. Supp. 1151 (E.D. La. 1997).
As these authorities note, scientific case studies reflect nothing more than anecdotal accounts of a particular incident and often fail to screen out alternative causes for the patient's reported condition. The 8th Circuit agreed that whatever association such case reports purportedly demonstrated was not scientifically valid proof of causation.
• Challenge testing. Glastetter's experts further relied on case studies involving "challenge testing." Challenge testing is performed on subjects believed to have experienced an adverse event from a specific cause. "Dechallenge" testing removes the drug exposure from a patient to determine whether the adverse reaction subsides. "Rechallenge" testing re-exposes a patient to the drug to see whether the adverse event reappears.
In Glastetter, the challenge tests did not involve the same circumstances as those that the plaintiff had experienced. The District Court also believed that such studies conducted with Parlodel were insufficient by themselves to establish causation. In particular, the District Court was concerned that such tests were conducted without standard scientific testing controls and were too few in number to provide statistically significant results.
Although the 8th Circuit concluded that these tests were more potent proof of causation than the District Court believed, it agreed that the exclusion of this evidence was within the District Court's discretion.
• FDA decision to rescind approval of Parlodel. In 1994, the FDA claimed that it had evidence calling into question the safety of bromocriptine, the active ingredient in Parlodel. The information purportedly indicated that bromocriptine was associated with an array of adverse events, including seizures and hypertension, and could be an additional risk factor for patients who are at risk for strokes. The FDA concluded that bromocriptine's potential risks outweighed its limited benefit in suppressing postpartum lactation and ordered it withdrawn from the market.
Glastetter argued that the FDA's risk-benefit determination under its regulatory mandate supported her own experts' opinions, making them admissible under Daubert. She argued that studies relied on by the FDA were reliable and admissible in court.
The 8th Circuit noted that the FDA acts under different, reduced standards than those required by traditional state tort law. Federal agencies like the FDA assume a preventive posture and are empowered to act even if causation is not established. The "FDA will remove a drug from the marketplace upon a lessor showing of harm to the public than the preponderance-of-the-evidence or more-likely-than-not standards used to assess tort liability." Thus, the 8th Circuit held that FDA findings alone were insufficient to support the opinions of Glastetter's experts.
As this summary of Glastetter reveals, federal courts cannot decide the admissibility of an expert opinion simply with a check of prior cases to see whether similar opinions were admitted in the past, indicating general acceptance of the expert's theory.
In contrast to the inquiry required of federal courts, the inquiry required by California's courts arguably may be far more abbreviated. But even without Daubert, state-court defendants may challenge expert testimony by raising the same underlying concerns through different means, such as by arguing that the expert's opinion is without adequate foundation.
But Glastetter underscores how powerful a tool Daubert can be when tort claims are litigated in the federal system. Moreover, the science itself must withstand scrutiny on multiple levels. Though expert testimony regarding causation always will be central to any tort litigation, the power of Daubert is a factor that all parties must account for and adjust to when that tort litigation is conducted in federal court.
David Stanley, a director with Crosby Heafey Roach & May in Los Angeles, and David De Jesus, an associate with the firms' Oakland office, specialize in medical-device and pharmaceutical product-liability litigation.
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