“Judges and other lawyers must learn how to deal with scientific evidence and inference.”

Late last year, a panel of 7th Circuit reversed an Administrative Law Judge (ALJ) who had upheld a citation and fine against Caterpillar Logistics, Inc. (Cat).  The panel, in a wonderfully succinct, but meaty decision by Judge Easterbrook, wrote of the importance of judges’ and lawyers’ learning to deal with scientific and statistical evidence. Caterpillar Logistics, Inc. v. Perez, 737 F.3d 1117 (7th Cir. 2013)

Pseudonymous MK, a worker in Cat’s packing department, developed epidcondylitis (tennis elbow).  Id. at 1118. OSHA regulations require employers to report injuries  “the work environment either caused or contributed to the resulting condition”. 29 C.F.R. § 1904.5(a). MK’s work required her to remove items from containers and place items in shipping cartons. The work was repetitive, but MK acknowledged that the work involved little or no impact or force.  Apparently, Cat gave some rather careful consideration to whether MK’s epidcondylitis was work related; it assembled a panel of three specialists in musculoskeletal disorders and two generalists to consider the matter.  The panel, relying upon NIOSH and AMA guidelines, rejected MK’s claim of work relatedness.  Both the NIOSH and the AMA guidelines conclude that repetitive motion in the absence of weight or impact does not cause epicondylitis. Id.

MK called an expert witness, Dr. Robert Harrison, a clinical professor of medicine, at the University of California, San Francisco.  Id. at 1118-1119.  Harrison unequivocally attributed MK’s condition to her work at Cat, but he failed to explain why no one else in Cat’s packing department ever developed the condition.  Id. at 1119.

Harrison acknowledged that epidemiologic evidence could confirm his opinion, but he dismissed such evidence as being able to disconfirm his opinion.  The ALJ echoed Dr. Harrison in holding epidemiologic evidence to be irrelevant:

“none of these [other] people are [sic] MK. Similar to the concept of the ‘eggshell skull’ plaintiff in civil litigation, you take your workers as they are.”

Id. at 1119-20, citing ALJ, at 2012 OSAHRC LEXIS 118 at *32.

Judge Easterbrook found this attempt to disqualify any opposing evidence to lie beyond the pale:

“Judges and other lawyers must learn how to deal with scientific evidence and inference.”

Id. (citing Jackson v. Pollion, 733 F.3d 786 (7th Cir. 2013).

Judge Easterbrook called out the ALJ for misunderstanding the nature of epidemiology and the role of statistics, in the examination of causation of health outcomes that have a baseline incidence or prevalence in the population:

“The way to test whether Harrison is correct is to look at data from thousands of workers in hundreds of workplaces—or at least to look at data about hundreds of worker-years in Caterpillar’s own workplace. Any given worker may have idiosyncratic susceptibility, though there’s no evidence that MK does. But the antecedent question is whether Harrison’s framework is sound, and short of new discoveries about human physiology only statistical analysis will reveal the answer. Any large sample of workers will contain people with idiosyncratic susceptibilities; the Law of Large Numbers ensures that their experience is accounted for. If studies of large numbers of workers show that the incidence of epicondylitis on jobs that entail repetitive motion but not force is no higher than for people who do not work in jobs requiring repetitive motion, then Harrison’s view has been refuted.”

Id. at 1120.

Judge Easterbrook acknowledged that Cat’s workplace evidence may have been a sample too small from which to draw a valid statistical inference, given the low base rate of epicondylitis in the general population.  Dr. Harrison’s and the ALJ’s stubborn refusal, however, to consider any disconfirming evidence, obviating the need to consider sample size and statistical power issues.

Finally,  Judge Easterbrook chastised the ALJ for dismissing Cat’s experience as irrelevant because many other employers will not have sufficient workforces or record keeping to offer similar evidence.  In Judge Easterbrook’s words:

“This is irrational. If the camera in a police car captures the events of a highspeed chase, the judiciary would not ignore that video just because other police cars lack cameras; likewise, if the police record an interrogation, courts will consider that information rather than wait for the day when all interrogations are recorded.”

Id. This decision illustrates why some commentators at places such as the Center for Progressive Reform get their knickers in a knot over the prospect of applying the strictures of Rule 702 to agency fact finding; they know it will make a difference.

As for the “idiosyncratic gambit,” this argument is made all too frequently in tort cases, with similar lack of predicate.  Plaintiffs claim that there may be a genetic or epigenetic susceptibility in a very small subset of the population, and that epidemiologic studies may miss this small, sequestered risk.  Right, and the light in the refrigerator may stay on when you close the door.  Prove it!