Kernicterus, the Daubert Decision, and Evidence-Based Medicine

Abstract

To the Editor.—The special article by Sartore and van Doren1 and the commentary by Brent2 draw attention to the Daubert decision that a court is required to decide whether medical expert testimony is scientifically valid. Notwithstanding the reservations expressed by Brent,2 the scientific community, generally, will applaud this decision. The authors also note that Daubert requires evidence from epidemiologic studies establishing a relative risk of >2.0 before the jury can conclude that there is a >50% likelihood that a putative cause produced the undesirable outcome. They then state that a Daubert motion could succeed in barring testimony by experts in cases of hyperbilirubinemia because there is “a paucity of medical literature to establish the relative risks of bilirubin-induced encephalopathy for neonates exposed to various levels or doses of bilirubin.”Although quantitative literature on this point is admittedly sparse, the causal relationship between hyperbilirubinemia and kernicterus is generally not disputed. In our experience, however, most malpractice cases involving kernicterus do not revolve around the question of whether a specific bilirubin level produced brain damage or whether an intervention at a lower bilirubin level would have prevented the damage. More commonly, cases involve infants admitted to the hospital with bilirubin levels of ≥35 mg/dL who manifest the classical signs of acute bilirubin encephalopathy. In these cases, the causal role of hyperbilirubinemia is not in doubt and, in most such cases, it can be asserted with “reasonable medical probability” that, if this infant had been seen and treated earlier, the bilirubin would not have risen to dangerous levels and the kernicterus could have been prevented. Whether someone is to blame for this sequence of events, however, is often the more contentious issue, and specifically whether there was a breech in the standard of care.We certainly want the court to assess the scientific validity of all expert testimony and advise the jury accordingly. Unfortunately, in many kernicterus malpractice cases, the jury is not asked to decide whether the particular bilirubin level was responsible for the brain damage; they are asked to decide if the physician's actions complied with the prevailing “standard of care.” In legal parlance this is generally defined as what a reasonable physician would do with the same or similar patient under the same or similar circumstances. Because scientific evidence on this question is generally limited, the jury is often left to decide which expert(s) to believe.