Plaintiff Anne Ruggiero appeals from a judgment entered by the United States District Court for the Southern District of New York (Kaplan, /.), dismissing on summary judgment a complaint alleging that her husband’s cirrhosis and death were caused by Rezulin, a diabetes medication manufactured and sold by defendants Warner-Lambert Co. and Parke Davis (“Defendants”). The ground for dismissal was that Ruggiero failed to produce sufficient evidence that Rezulin was capable of causing or exacerbating cirrhosis (so-called “general” causation). On appeal, Ruggiero argues principally that [i] the ruling on general causation was error because that issue was first raised in Defendants’ summary-judgment reply papers, and is a subject of on-going consolidated proceedings in the multi-district litigation (“MDL”) of which Ruggiero’s case is part; and [ii] medical expert evidence attributing Mr. Ruggiero’s cirrhosis and death to Rezulin was erroneously ruled inadmissible. For the following reasons, we affirm.
BACKGROUND
Albert Ruggiero was diagnosed with Type-II diabetes in 1982, and in May 1997, he began taking Rezulin, a diabetes medication manufactured and sold by Defendants. His death on August 24, 1998 was attributed to liver failure caused by cirrhosis. On March 21, 2000, Defendants halted distribution of Rezulin at the request of the Food and Drug Administration, in light of concerns that the drug caused increased liver toxicity.
Anne Ruggiero commenced this product-liability action, claiming that Rezulin caused Albert’s cirrhosis. The case was added to the “[m]ore than one thousand” Rezulin-related cases consolidated for pretrial proceedings in the Southern District of New York, before Judge Kaplan.
In re Rezulin Prods. Liab. Litig. (MDL No. 1848),
The district court granted summary judgment, holding that Ruggiero produced insufficient evidence of “general” causation,
i.e.,
evidence that Rezulin is capable of causing or exacerbating cirrhosis of the liver.
1
Specifically, the court ruled that the sole evidence of general causation submitted by Ruggiero — the expert opinion of Dr. Douglas T. Dietrich — was inadmissible (as to that issue) under Fed R. Evid. 702 (“Testimony by Experts”) and
Daubert v. Merrell Dow Pharmaceuticals,
DISCUSSION
We review the grant of summary judgment
de novo. See Anthony v. City of New York,
I
As a threshold matter, Ruggiero claims that the district court should not have reached the issue of general causation.
First, she argues that the issue was first raised in Defendants’ summary-judgment reply papers.
See, e.g., Playboy Enters., Inc. v. Dumas,
Defendants’ moving papers did not argue expressly in terms of general causation. However [i] the motion was cast in terms of the broader and subsuming argument that Ruggiero could not “establish the essential element of causation”; [ii] a declaration appended to the moving papers noted that “[tjhere are no scientific studies in the medical literature that conclude Rezulin can cause cirrhosis”; and [iii] Ruggiero’s opposition papers cited as a genuine issue of material fact “[wjhether or not there are scientific studies in the medical literature that conclude Rezulin can cause liver failure such as caused decedent Albert Ruggiero’s death.” Under the circumstances, Ruggiero cannot claim that she was blindsided by Defendants’ reliance on general causation or that she was prejudiced by the district court’s consideration of that issue. 3 In any event, it is hard for Ruggiero to claim unfair prejudice now, because she could have claimed surprise in the district court and sought to file a responsive sur-reply. 4
*253 Second, Ruggiero argues that the district court should not have considered the issue of general causation because that issue [i] is being litigated by the “Plaintiffs Executive Committee” in the consolidated MDL proceedings and [ii] implicates the law-of-the-case doctrine by reason of a previous contrary decision in those consolidated proceedings (or somewhere else). Even assuming that the law-of-the-case doctrine would apply, Ruggiero’s brief directs us to no such contrary ruling.
In any event, we decline to consider the merits of this argument because Ruggiero failed to present it to the district court.
Id.
We have discretion to consider issues that a party failed to raise in the district court,
see Booking v. Gen. Star Mgmt. Co.,
II
The district court granted summary judgment to Defendants on the ground that Ruggiero submitted no admissible evidence to show, as a matter of general causation, that Rezulin can cause or exacerbate cirrhosis of the liver. Her only submission arguably on point was the expert opinion of Dr. Dietrich, who concluded with reasonable medical certainty that “Albert Ruggiero’s liver disease was caused by his taking Rezulin.” The district court ruled it inadmissible under the standards set out in Fed.R.Evid. 702 and Daubert.
Rule 702 states:
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, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.
As the Supreme Court explained in
Dau-bert,
Rule 702 requires the district court to ensure that “any and all scientific testimony or evidence admitted is not only relevant, but reliable.”
A district court’s decision as to how the reliability of expert testimony should
*254
be determined, as well as the ultimate decision as to whether that testimony is reliable, are reviewed for abuse of discretion.
See Kumho Tire Co. v. Carmichael,
Judge Kaplan applied the Daubert factors and concluded that there was no reliable basis for Dr. Dietrich’s opinion that Rezulin could cause or exacerbate cirrhosis of the liver: “Dr. Dietrich was unable to point to any studies or, for that matter, anything else that suggested that cirrhosis could be caused or exacerbated by Rezulin.” The judge further concluded that insofar as Dr. Dietrich’s opinion relied on a differential diagnosis, that technique was insufficiently reliable to support the opinion as to general causation (though it might suffice to support an opinion that a drug shown to be capable of causing the condition likely did so in a particular case).
We see no error. A 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.”
Hall v. Baxter Healthcare Corp.,
We cannot say that a differential diagnosis
may never
provide a sufficient basis for an opinion as to general causation. There may be instances where, because of the rigor of differential diagnosis performed, the expert’s training and experience, the type of illness or injury at issue, or some other case-specific circumstance, a differential diagnosis is sufficient to support an expert’s opinion in support of both general and specific causation.
Cf. McCulloch v. H.B. Fuller Co.,
*255
As a final matter, Ruggiero — relying on language in
McCulloch
— argues that any fault in Dr. Dietrich’s use of a differential diagnosis goes to weight, not admissibility. After the
McCulloch
Court reviewed a number of factors underlying the opinion of the plaintiffs expert, the Court stated that “[disputes as to the strength of his credentials, faults in his use of differential etiology as a methodology, or lack of textual authority for his opinion, go to the weight, not the admissibility, of his testimony.”
Id.
at 1044. Ruggiero is over-reading that passage. The opinion had held, supra, that the district court did not abuse its discretion in ruling that the expert’s opinion
in that case
was admissible; in the quoted passage, the Court was merely signaling that any remaining objection as to the expert’s credentials or methodology was for the consideration of the jury. In any event, Ruggiero’s reading of
McCulloch
is precluded by the Supreme Court’s subsequent decision in
Joiner.
In
Joiner,
the Court held that “conclusions and methodology are not entirely distinct from one another,” and that “[a] court may conclude that there is simply too great an analytical gap between the data and the opinion proffered.”
❖ * * sji * *
We have considered Ruggiero’s remaining arguments and find each to be without merit. The judgment of the district court is affirmed.
Notes
. General causation bears on whether
the type of injury at issue can be caused or exacerbated
by the defendant's product. “Specific" causation bears on whether, in the particular instance,
the injury actually was caused or exacerbated
by the defendant's product.
See Amorgianos v. Nat’l R.R. Passenger Corp.,
. The district court assumed for the purpose of analysis that Dietrich relied on a differential diagnosis but noted that "it was not really clear” that he did so.
.
See, e.g., Bayway,
.
See, e.g., Bayway,
. On this score, the district court indicated that even if a differential diagnosis could be probative of general causation in an appropriate case, it was not so here:
*255 It is not at all clear ... that a district court lacks discretion to conclude in an individual case that an expert's opinion as to general causation based on an unreliable differential diagnosis must be received in evidence.
This case illustrates the fundamental problem with differential diagnosis .... The doctor has not offered any reliable basis for concluding that Rezulin is capable of causing the cirrhosis that caused the liver failure that resulted in Mr. Ruggiero’s death. In other words, he has offered no reliable ground upon which Rezulin may be “ruled in" as a plausible cause of the cirrhosis.
