Delaware Court Rejects Expert Causation Testimony Based Solely on Temporal Relationship
The court handling Delaware's Seroquel cases recently issued a thoughtful opinion analyzing the admissibility of medical causation testimony. See Hopkins v. AstraZeneca Pharmaceuticals, LP, 2010 WL 1267219 (Del. Super. -- New Castle Co. Mar. 31, 2010).
In Hopkins, plaintiff was a morbidly obese woman whose family history and medical condition put her at a substantially increased risk of developing Type II diabetes. She began taking Seroquel as a sleep aid in January 2003, and stopped after less than two years, when she was diagnosed with Type II diabetes. Plaintiff sued Seroquel's manufacturer, alleging that the medicine caused her to develop diabetes. The defendant moved for summary judgment, arguing that plaintiff had no credible proof of specific causation.
In response, plaintiff proffered the testimony of Dr. Loren W. Greene, a Clinical Associate Professor of Medicine at NYU School of Medicine who is board certified in Internal Medicine as well as Endocrinology and Metabolism. Id. at *3. The defendant did not challenge Dr. Greene's qualifications.
It did, however, challenge her methodology. The defendant argued that Dr. Greene could not give an opinion to a reasonable degree of medical certainty as to how Seroquel causes diabetes, and she could not isolate Seroquel from the other potential causes. Her opinion, at its core, was a temporal association: because plaintiff had not developed Type II diabetes before, it must be that she developed diabetes shortly after taking Seroquel because of the Seroquel. Id. at *5-*6. And yet Dr. Greene could not rule out chronic morbid obesity as the sole cause of plaintiff's diabetes. Id. at *6.
Delaware follows Daubert and has adopted an identical version of Rule 702 requiring expert testimony to be based on sufficient data, reliable principles, and the reliable application of those principles to the facts of the case. The court ultimately held that Dr. Greene's testimony was inadmissible because she: (1) failed to adequately explain her methodology, (2) placed too much emphasis on the temporal relationship, (3) failed to rule out other likely causes, and (4) failed to explain how she incorporated data from epidemiological studies and clinical studies into her analysis.
Because Dr. Greene's specific causation testimony was inadmissible, the court granted the defendant's motion for summary judgment against plaintiff.
The opinion in Hopkins is an example of a very workmanlike approach to the admissibility of scientific expert testimony. It takes the court's gatekeeping function seriously, while not erecting impossible burdens for the expert to overcome. Clearly, the court was influenced by the fact that much of the expert's deposition was spent answering "I don't recall" to questions about studies forming the basic underlying theory of general causation.
One often wonders what the subsequent impact is of judicial opinions rejecting expert testimony for failure to follow the scientific method. For example, does any sort of review board take up the issue of a medical professor's methodology when it has been rejected by a court of law? To the extent a treating physician and professor has, in paid testimony, reached a conclusion on specific causation without excluding other likely causes of the condition, should that have any relevance beyond the litigation context?
