I authored an article on Texas' standard(s) for proof of causation that appeared in this week's Texas Lawyer and it contains an error. In discussing Merck v. Garza I somehow managed, during the process of editing the article down to the target word count, to associate the citation from the original appellate court opinion with the decidedly different conclusion reached by the Texas Supreme Court to which I was referring. My bad.
The United States Court of Appeals, First Circuit, has delivered an opinion about the duty borne by trial courts to keep out flawed analyses by credentialed experts that is as keen in its reasoning as it is sharp in its prose. It's "Samaan v. St. Joseph Hospital".
Have you ever despaired of explaining that a 50% increased risk doesn't mean that half of those exposed are going to come down with the ailment associated with the elevated risk? Or that a big increase in a tiny risk rarely has anything to say about causation? Take a copy of Samaan with you the next time it comes up and have the following to hand:
" When a person's chances of a better outcome are 50% greater with treatment (relative to the chances of those who were not treated), that is not the same as a person having a greater than 50% chance of experiencing the better outcome with treatment. The latter meets the required standard for causation; the former does not.
To illustrate, suppose that studies have shown that 10 out of a group of 100 people who do not eat bananas will die of cancer, as compared to 15 out of a group of 100 who do eat bananas. The banana-eating group would have an odds ratio of 1.5 or a 50% greater chance of getting cancer than those who eschew bananas. But this is a far cry from showing that a person who eats bananas is more likely than not to get cancer. Even if we were to look only at the fifteen persons in the banana-eating group who did get cancer, it would not be likely that any particular person in that cohort got it from the consumption of bananas. Correlation is not causation, and a substantial number of persons with cancer within the banana-eating group would in all probability have contracted the disease whether or not they ate bananas."
And then there's this:
"Many aspects of science are a mystery to laymen without the aid of experts. In the world of the blind, the one-eyed man is king; and Daubert relevancy is the sentry that guards against the tyranny of experts. As the gatekeeper, the trial judge has the duty to insulate the jury from expert testimony when reliance on authoritative studies and methods threatens to mask the lack of an adequate fit. An expert might be able to testify on the phases of the moon to prove that it was dark by a particular time, but he could not offer the same testimony to prove that a person was likely to act in an unusual manner on that night."
But best of all and a bit earlier on in the opinion the court makes it clear that evidence, rather than mere conjecture, is required before a citizen is relieved of his property:
"The reliable foundation requirement necessitates an inquiry into the methodology and the basis for an expert's opinion. To perform the required analysis, the district court must consider a number of factors, including but not limited to "the verifiability of the expert's theory or technique, the error rate inherent therein, whether the theory or technique has been published and/or subjected to peer review, and its level of acceptance within the scientific community." Ruiz-Troche, 161 F.3d at 81. Given the nature of this analysis, the expert's methodology is commonly the "central focus of a Daubert inquiry." Id.
The second requirement has attracted less attention. This requirement seeks to ensure that there is an adequate fit between the expert's methods and his conclusions. See Daubert, 509 U.S. at 591. This prong of the Daubert inquiry addresses the problem that arises when an expert's methods, though impeccable, yield results that bear a dubious relationship to the questions on which he proposes to opine." (Emphasis added).So, how to reconcile Saaman with Milward? I'm afraid it can't be done.
Tau hyperphosphorylation is a pretty common finding in young and middle-aged people with no cognitive impairment and has many causes, including physical and emotional ones.
Extrapleural pneumonectomy: runs up the damages, runs down the patient.
The science of epidemiology is coming to grips with the following facts: a) no "big" risk factors have been discovered in quite awhile and the future looks to consist mainly in attempting to uncover tiny ones; b) even when big risks in a population are identified the knowledge does not translate into making sound predictions about individuals; because c) chance, or luck, plays a huge role in whether or not we'll get sick, whatever our exposures. That's my take on an article you need to read if you're at all interested in epidemiology - it's "Epidemiology, Epigenetics and the 'Gloomy Prospect': Embracing Randomness in Population Health Research and Practice".
Below are a few lines from the exceptionally well written piece to whet your appetite:
"We should embrace the effects of chance, rather than pretend to be able to discipline them."
"The pioneering epigeneticist Robin Holliday points out that it is commonly stated that disease is either genetic or environmental, when in reality stochastic events are equally important."
"Epidemiological inference is to the group, not to the individual"
"... the determinants of the incidence rate experienced by a population may explain little of the variation in risk between individuals within the population."
"Chance (at one level) and near necessity (at another) may be the only certainty in attempting to understand epidemiological - and many other - processes."
"At a group level, the underlying social causes of IHD (ischemic heart disease) could be social and political structure, sequentially mediated through free trade in toxic microenvironments, in health-related behaviours, and in the elevated body mass index, blood pressure, serum cholesterol, glucose and insulin. At an individual level, it is mostly genes and chance."
"... in terms of public health policy, we should target the modifiable causes of disease that heritability and shared environment tell us about. This must be at the group level, however, and we should do so without pretending to understand individual-level risk, or misrepresent population level data (smokers die earlier on average) as individual level events (each smoker shortens her or his life."
Pay special attention to the section on "lay epidemiology". The narratives we create about our lives, cast in terms of fate, or chance, turn out to be a lot closer to the mark than most epidemiologists have been willing to admit.
h/t Garth Brooks
Today the U.S. Supreme Court denied U.S. Steel's petition for writ of certiorari in Milward v. Acuity. As a result plaintiffs' expert is now free to testify about his untested and in fact untestable hypothesis. It's a shame because the First Court of Appeals has apparently lost sight of what science, at least reliable science, is all about.
Consider "Trials and Errors: Why Science is Failing Us". The article describes what was deemed the shocking failure of torcetrapib - a drug designed to prevent so-called "good" cholesterol (HDL) from converting into "bad" cholesterol (LDL). Noting that "[t]here was a vast amount of research" supporting the proposition that increasing the HDL:LDL ratio would prevent coronary artery disease, and given that "the cholesterol pathway is one of the best-understood biological feedback systems in the human body", scientists assumed that they knew how torcetrapib would act and that its effect would be positive. Instead, "the drug appeared to be killing people."
Rather than a failure of science the story of torcetrapib should be viewed as a triumph, at least so long as science is viewed as a method for subjecting big ideas to the acid bath of skepticism rather than the hatching of seemingly clever notions. Milward, by allowing an expert to base his causation opinion on nothing more than a plausible hypothesis consisting of a proposed biologic mechanism far less well understood than that of the cholesterol pathway, embraces the big idea view of science.
The debate is an old one but one in which common law countries have generally sided with the scientific method over mere idealism. Perhaps it has something to do with the experience of French and English bridge designers. The early French suspension bridges had an unfortunate tendency to collapse despite being beautiful whereas the English versions tended to be ugly but sturdy. For the French designers the thought was "it must stand because it is so beautiful". For the English the idea was "it must stand or I shall be fired".
The opinions of experts should be no less tested and no less reliable than bridges as both have so much riding on them.
Want to look and feel younger? Well, there's a properly done study, statistically significant at p < .05, showing that people who listen to The Beatles "When I'm Sixty-Four" actually became a year and a half younger! Far fetched? Sure, but no more so than umpteen conclusions published in the scientific literature every day purporting to establish some causal connection based on nothing more than a statistical analysis of a series of observations. That's the point demonstrated conclusively in False-Positive Psychology: Undisclosed Flexibility in Data Collection and Analysis Allows Presenting Anything as Significant.
Though a paper may validly claim that the likelihood of the reported causal connection being due to chance alone is 5% or less (i.e. p < .05), "False-Positive Psychology" demonstrates that researchers free to modify as few as four variables (such as the number of observations to be made, sorting those observed by gender or stratifying outcomes) more likely than not have "discovered" a causal association that doesn't exist. The harm done by publishing such false-positives are obvious. As the authors put it:
"First, once they appear in the literature, false positives are particularly persistent. Because null results have many possible causes, failures to replicate previous findings are never conclusive. Furthermore, because it is uncommon for prestigious journals to publish null findings or exact replications, researchers have little incentive to even attempt them. Second, false positives waste resources: They inspire investment in fruitless research programs and can lead to ineffective policy changes. Finally, a field known for publishing false positives risks losing its credibility."
To vaccinate against infecting the scientific literature with false-positives the authors conclude with suggestions similar to those we've seen elsewhere in efforts to promote evidence-based science. At the heart of the suggested approach is transparency from the moment the experiment is conceived all the way through publication. There are six for authors and four for reviewers; be sure to read them all.
The NYTimes says extra sodium threatens all but a new study says normal people just excrete it
The XMRV / CFS (Chronic Fatigue Syndrome) fiasco is simply an example of how science works
European study finds increased risk of death (CVD and heart failure) for Avandia vs pioglitazone beginning shortly after initiation, and disappearing upon discontinuation, of treatment
Can Vitamin D prevent fractures and even cancer? The evidence is mostly all over the board
Paternal, but not maternal, smoking is associated with an increased risk of childhood leukemia
I meant to put this up on Halloween but a trial got in the way; it's only relevant to mass tort litigation if you've been paying attention:
It's no longer contested that certain microbes can hijack the brains of invertebrates and of vertebrates, including mammals.
But is there evidence that microbes can affect human behavior? Lots:
Do gut microbes influence the central nervous system? Yes.
Do microbes talk to your brain? Yes.
Can microbes make you anxious? Yes.
Are microbes likely the cause of schizophrenia and other behavior disorders? Yes.
Do they also cause personality disorders like neuroticism? Yep. (link to follow ;) )
Plaintiff's expert Martyn Smith has proposed a mechanism whereby benzene produces leukemia.
Night shift work modestly increases women's risk of obesity and thus their risk of diabetes.
Soy milk may make your baby girl grow up to be considerably less feminine.
I keep coming up with reasons to pass on my father-in-law's venison stew/boudin/sausage/etc.
It's not clear whether acetaminophen causes asthma or whether the flu is to blame.
Aspirin really does reduce the risk of colon cancer in those predisposed to it.
Even the best speakers, they who speak with the greatest ease and grace, appear to me almost with an air of impudence, unless they compose themselves to speak with a certain bashfulness, and are under some confusion when they set out; yet they can never appear otherwise; for the more a man excels in speaking, he is the more sensible of its difficulty, he is under the greater concern for the event of his speech, and to answer to expectation of the public.
- Cicero "De Oratore"
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