Day 215: Headlong into year 3! .....

The Montreal tobacco trials passed another milestone today. It was two years ago today that courtroom 17.09 was filled to the rafters with those who had come to see the opening of this historic event.

Today, there was an over-flow crowd on the lawyers' benches ahead of the bar, but the only non-participants in the audience were the three regular note-takers: your two humble bloggers and a lawyer who represents the insurance company that might be on the hook for the legal fees for Imperial Tobacco and Rothmans, Benson and Hedges.

The occasion did not go unmarked, however. As everyone was settling into theirs seats, Justice Riordan greeted the room: "Before we start I would like to wish everyone a happy anniversary."  

In a courtroom, every anniversary is a paper anniversary.

A two-day interval of no-confidence

The beginning of the week was spent reviewing the criticisms of the statistician hired by JTI-Macdonald regarding the plaintiffs' experts' estimate of the number of Quebecers who suffered from the diseases covered by the Blais side of the Blais-Létourneau twinned class action suits.

Mr. Laurentius Marais did not hold back!

For two long days he had elaborated on the many and varied faults he found in the report of Montreal epidemiologist, Jack Siemiatycki. (Mr. Symiatycki's expert report is Exhibit 1426.1; Mr. Marais' expert report is Exhibit 40549).

His conclusions were unambiguous, and there was no sugar-coating. He saw no statistical validity to Mr. Siemiatycki's estimates, and said that nothing reliable could be produced from his methods. In getting to this point, he had also thrown a lot of mud at the many component pieces of the meta-analysis conducted by Mr. Siemiatycki.

Mr. Marais is only the first. Two other experts have been hired to beat-up on Mr. Symiatycki's report, and by yesterday evening it was already beginning to look a little bruised.

As they left the court-room last night, the plaintiff lawyers looked more than a little pensive. They had only one day (today!) of cross-examination of this witness. How best to wipe the mud off the Siemiatycki report and put the air back in its tires?

Mr. André Lespérance and Mr. Bruce Johnston were the lawyers assigned to the cross-examination, and when they returned today they looked more confident. As they frequently do, they put themselves in a good-cop/bad-cop sequence. Mr. Lespérance would politely try to elicit admissions, and Mr. Johnston would less gently challenge Mr. Marais' credibility.

The KISS (keep it simple, stupid) principle

Mr. Marais is a man with an obvious fondness for precision. Yesterday, I had felt that he was willing to focus on precise details on the trees to obscure the forest, but in his answers today I recognized no attempts to divert attention from the facts he was being asked by the plaintiffs to acknowledge.

Mr. Lespérance was soon able to use this perhaps unexpected candour to good effect.

He spent the morning inviting Mr. Marais to acknowledge the condition of the forest of population-level effects. The witness, after rephrasing the question into more precise language, seemed happy to acknowledge the central health issues behind the Blais case.

A) The "vast majority" of lung cancers are caused by smoking

Of the thousands of exhibits that are now part of the trial, many hundred were presented by JTI-Macdonald's counsel, including a heavy number of scientific publications. Around 100 scientific articles were introduced as exhibits to support Mr. Marais' report.

Beginning with the reliance material Mr. Marais had himself selected, and then with other papers entered as evidence by JTI-Macdonald, Mr. Lespérance drew attention to the conclusions of many scientists that by far the greatest number of lung cancers were caused by smoking.

Mr. Marais was quick to agree that there was a "consensus"  that the "vast majority" of lung cancers were caused by smoking. He volunteered, without being asked, that the range of was "somewhat north of 75%" and went up to 80% to 90%. He did not quarrel with the many reports shown to him that gave the higher figure.

Check!

B) Relative Risk translates into population level effects

As if he had not spent two days critiquing calculation methods, Mr. Marais was surprisingly willing to confirm the relatively simple arithmetic operations presented to him to translate calculated relative risks from smoking into estimates of how much disease could be attributed to tobacco.

What would be the percent of excess cases in a population in which there had been a 20 fold increase in risk? "Then it follows that 19 out of 20 of those cases [of exposed individuals] are additional cases because of the exposure - 95%"

Check!

C) "2" is an important threshold value for Relative Risk 

Earlier this week, Mr. Marais had laid as a foundation of his critique what he saw as the misuse of estimates of risk when the range defined by the confidence interval fell below the value of "2" (2 is the value where risk is doubled, with the consequence that the "excess" risk exceeds the background risk.)

But when Mr. Lespérance showed him a review of risk of cancer from radon (Exhibit 1699), Mr. Marais allowed that even when the confidence interval fell below 2, one could make conclusions about "general causation."  

He acknowledged that his concerns about specific causation did not apply to general causation. "It is quite different from saying [it] is not a cause of lung cancer in general."

Check!

D) 3 to 5 pack years doubles the risk of lung cancer - at least according to one local study

Mr. Siemiatycki had chosen to conduct a meta-analysis in order to expand the evidentiary foundation of his conclusions about lung cancer and smoking. (He was the author of one of only a few studies on Canadian populations).

It was this meta-analysis prepared for his expert report that had come under such strong attack.

But what if the court relied only on a study conducted about Montrealers? (The only study on the court record is one also done by Mr. Siemiatycki, in 1995. (Exhibit 1428)

Mr. Marais had re-calculated the results of the study (Exhibit 40549C). He was asked to look at this work, and how many pack years his re-calculations showed were necessary before the risk of lung cancer had doubled. Did they not show that "the critical amount would be between 3 and 5 years," Mr. Lespérance suggested.

Mr. Marais agreed. "That would be the implication of these data." 

Check!

The other shoe

Bruce Johnston's questions, which took the second half of the day, were focused on providing Justice Riordan with reasons to put less confidence in Mr. Marais' testimony.

He contrasted the ethical norms of the American Statistical Association (Exhibit 1697) to the use of statistics by tobacco companies in trials (Exhibit 1701), and to a report of Mr. Marais's anticipated testimony at a previous trial (Exhibit 1704). He connected Mr Marais' seemingly unsurmountable methodological concerns to a strategy articulated by one his other client companies of setting an impossible level for proof.  (Exhibit 1702R)

Mr. Marais came out of this wrestling match pretty much unscathed. The same cannot be said for his clients.

One of the issues at this trial is whether it was ever reasonable for the companies to maintain that it had not been proven that smoking caused cancer. Mr. Marais, whose high standards for statistical proof had already been made clear, explained why he had reached this conclusion over 20 years ago.

It was not just the "many epidemiological studies of different kinds which demonstrated and documented over decades the strength of the association,"  or the strong consensus of experts, he said. The kicker for him was that no one had ever provided an alternative explanation, or revealed "the hidden factor" of another cause. "There was lots of opportunity for it to have been discovered."

Leaving the judge empty-handed

The three industry witnesses who have reviewed Mr. Siemiatycki's report have two things in common: they think the plaintiffs' epidemiologist's numbers are wrong, and they don't have any right numbers to propose. The strategy seems to be to leave the judge with nothing to work with.

Justice Riordan's questions at the end of the day suggested this is not a position he wants to be in.

"You have come in and you have criticized at length the steps in the method that is applied in trying to fulfill a mandate of coming to a number of sufferers of disease that are likely caused by smoking. Did you do any calculations yourself, after seeing the weaknesses in [Mr. Siemiatycki's] case? Did you estimate the number of people with lung cancer likely to be have caused by smoking?"

"I did not perform an independent study, no."

The judge asked whether the number of pack years required to give a relative risk of 2 could be produced, and Mr. Marais replied that it could only be done with a new study involving thousands of people.

Judge Riordan clarified whether with existing "published information, is it possible to do this?"  Mr. Marais was definitive in his answer. No. "I do not see a method that I could recommend to the court based on the information that I am aware of as I stand here today." 

Seconds later, Mr. Marais was being wished a safe trip home.

The second related witness, Mr. Kenneth Mundt, was expected to testify tomorrow. Instead, for unexplained reasons, the schedule was changed. He and Bertram Price have been rescheduled for the first half of next week.

It feels like a cliff-hanger: Will the companies use the long weekend come up with a new plan and respond to Justice Riordan's clear hints for some numbers to work with?

The trial resumes on Monday.

Day 214: Individuation.

At first it was a leit motif, but now it is a drum-beat.

The tobacco defence in the Blais-Létourneau trial is hitting hard on the very idea of wronged smokers as a collectivity. Today's witness insisted that even the calculation of a common level of harmful exposure to smoke is inappropriate.

Statistician Mr. Laurentius Marais made clear that he thinks it is impossible to use epidemiology to decide whether a smoker with cancer can be considered more likely than not to have become ill as a result of smoking, no matter how much he or she smoked.

Are they trying to hang their hat on a Howard Engle break-up-the-class hook?

Backing away from a population-wide approach

Mr. Marais was engaged by JTI-Macdonald to "review and comment on" the analysis prepared for the plaintiffs by Montreal epidemiologist, Jack Siemiatycki.

Mr. Siemiatycki had estimated that over 100,000 Quebecers suffered from the four diseases involved in the Blais lawsuit as a result of smoking. From the amount of illness attributed to smoking, he calculated how much additional risk a smoker would have to face before one could say that their illness was more likely than not to have been caused by smoking (a doubled risk). Combining studies on risk,, he calculated that this level of risk happened if someone smoked a pack of cigarettes a day for 3-5 years, depending on which illness was involved.

Mr. Siemiatycki's report was novel in that it translated the well established link between smoking and disease into workable numbers that could be applied in a mass tort-class action.

Now it is the industry witnesses' turn to try to reverse that work. By trying to smash Justice Riordan's confidence in Mr. Siemiatycki's calculations, Mr Marais seems to be the advance scout in a campaign to unravel the logic of collective recovery. Decertification by the back door?

Death by a thousand cuts

Mr. Marais seemed to have an endless pile of criticisms against Mr. Siemiatycki's work, and a long list of unrecoverable fatal flaws that he felt were made by one of Canada's more renowned epidemiologists.

"With the greatest of respect for Dr. Siemiatycki' he would begin, in a somewhat mannered delivery, only to follow up with a harsh, if diplomatically phrased, attack.

Dr. Siemiatycki's methods were wrong. His assumptions were wrong. His model was wrong. His slopes were wrong. There were mistakes in his calculations. The results are unreplicable. The conclusions are unusable.

So many criticisms - large and small - seemed intended to overwhelm. And why not?  Epidemiology and statistics are, let's face it, a little mysterious. And with that mystery, perhaps, a little mischief.

Mr. Marais certainly explained some things very clearly, and at length. But more than once he moved smoothly from the over-explained to the under-explained, ending up with a conclusion that directly opposed Mr. Siemiatycki's, without an overly clear trail of how he got there.

Is this a technique to make the juror or judge think that they are to blame for not following or understanding?

Wool over Eyes?

Even with my limited grasp of statistics, I heard explanations that seemed designed to obscure more than enlighten.

Yesterday, Justice Riordan had asked a question the answer to which, I thought, would have been an explanation of standard deviation. ("If you do a study and the average height is 5'9", plus or minus 4" then could I not be comfortable in assuming, at 95% confidence that any individual who came in would be at least 5'5"?)

The answer he was given by Mr. Marais, amplified this morning, did not provide him with this statistical tool. Instead it directed him to think that nothing could be derived from the mean.

Another questionable illustration today came in the form of a visualization of how "random effects model" (don't ask!) was a false way to make inferences in meta-analyses.

He presented a graph suggesting that such an approach would falsely predict Quebec self-reported obesity rates, and would lead one to think they are in the middle of the pack of North American levels, instead of at a much lower value. [His illustration, with the Quebec value shown as a red dot, is shown below].

Justice Riordan seemed quite taken with this -- "I find that very interesting."

Say again?  Creating comparative groups by measuring against number of jurisdictions, not number of people?? Selecting the fattest global population (USA) as your frame of reference?

To my eyes, it seemed to illustrate the problems with bad data and fuzzy thinking, not techniques within the meta-analysis machine. But, Judge Riordan found it very interesting, and he was the audience.

The bottom line: no threshold value to attribute legal responsibility. 

Mr. Marais made clear that he felt that Mr. Siemiatycki had consistently biased his results to create a larger number of potential claimants. His slope for he dose-response was too high, and it was anchored at the wrong point. A curvilinear dose-response would produce lower values, etc.

These, together with his elaborated concerns with confidence levels, lead him to conclude that it was not possible to find any "statistically reliable" threshold level of smoking that could be used to attribute responsibility to cigarettes. "Not 5 pack years, not 50 pack years, not 150 pack years!"

So where does that leave the judge?

Mr. Marais seems to have been under instruction to offer only negative criticism of the plaintiffs' estimates of the harms done by smoking, and not to propose an alternative way of measuring how many people have become ill through smoking.

Close to the end of Mr. Pratte's questions, Justice Riordan addressed the lawyer and suggested that Quebec law did not require the perfect to be the enemy of the good.

"I hear everything that Dr. Marais is saying – it is very interesting testimony. This man is a scientist and is very competent. But I have a different role than a peer reviewer. My level of satisfaction is dictated to me by the Civil Code - Article 2804;--- Evidence is sufficient if it renders the existence of a fact more probable than its non-existence -- That is the test that I have to apply.

This testimony is on point and well founded within the confines of a scientific debate – But it is only fair to let you know that I think there is something else I have to look at." 

A final volley

Mr. Pratte acknowledged the unusual intervention, but did not seem to deviate from his prepared questions.

He asked his witness to again beat on the drum of individuation. "The probability of causation ... is not a concept that evaluates or assesses or describes any individual person. It is a descriptive measure on average of an entire population." 

Dr. Siemiatycki's approach, even if it were not replete with problems, would result in "over-counting and overcompensation" of those who are close to the threshold value of a relative risk of 2. "Only 50 out of 100 cases would have been caused by the exposure .. but the court would be accepting 100 out of 100." 

(He did not draw attention to the under-counting and under-exposure on the other side of the threshold, for whom the court would be rejecting 100 out of 100, even if 50 had become ill as a result of exposure).

Nor could a higher level of threshold risk be set. There was "simply no place that the meta analysis lead you to as the appropriate critical amount."  There was no scientific consensus in favour of a "balance of probabilities" approach, which was  a "hugely controversial point" among scholars.

Mr. Pratte's last questions asked him to confirm the importance of variables that made Quebec smokers different from one another  -- when they started smoking, whether they had quit, and how long ago, how heavily they smoked. 

The court adjourned at 3:00 p.m. Tomorrow - the second anniversary of this trial - the plaintiffs will cross-examine Mr. Marais.

Day 213: Not your "average" kind of witness

Good news should travel fast! Justice Robert Mongeon issued his decision last Friday to the tobacco industry's constitutional challenge to the the law which underpins the Quebec government lawsuit. Five long months have passed since he listened to a week of arguments.  Spoiler alert! Justice Mongeon's ruling is not yet available on Quebec's SOQUIJ database of rulings. But why wait to read the details before knowing that those who were celebrating on the weekend were the Quebec government's legal team, on whose side Justice Mongeon came down firmly. He ruled that the provisions of the Tobacco-related Damages and Health Care Costs Recovery Act, taken in isolation or as a whole, did not offend either Article 23 (right to a fair trial) or Article 6 (property rights) of Quebec's Charter of Human Rights and Freedoms. The law was "clear and unambiguous" he wrote, in the way it eliminated a limitation period and was therefore consistent with the Charter.

Oh, my goodness. It's already March, the clocks have been pushed forward and we are entering what may be the last witness-sprint in the Montreal Tobacco Trials. Is the end really coming into sight?

Certainly, there was an atmosphere of end-of-term intensity in the courtroom when the lawyers for the 5 parties re-assembled this morning. (The regular one-week-a-month break came after a very reduced sitting schedule for February).

All sides were there in full force for the beginning of one of the more strategically important moments at this trial: the assault on the plaintiff's expert epidemiologist.

Last year, Mr. Jack Siemiatycki presented his estimate of the number of Quebec smokers  (110,282 people) who have fallen victim to one of the the four diseases included in the Blais class action. He calculated the number of years one would have to smoke at the rate of a pack-a-day before such diseases could be considered  - more likely than not - to have been caused by smoking (3 to 5 pack-years).

Justice Riordan seemed quite accepting of these numbers, and Dr. Siemiatycki's opinion clearly influenced his ruling for a new definition of class members in the Blais case.

Something to aim at

Mr. Siemiatycki's report feels like the foundation of the Blais disease-case. It quantifies the harm, sets a threshold for the number of deaths that can be "legally attributable" to smoking, and establishes the rationale for treating claimants as a population, instead of just an aggregation of individuals.

That's why for the tobacco industry's side, it is THE bulls-eye to aim for. A knock-down punch on Mr. Siemiatycki's analysis could destroy the logic of collective recovery in this trial, or at least re-route it towards Engle-style individual claims.

Three skilled witnesses are lined up to take a goat the report over the next two weeks of trial. The first, today's witness, is Laurentius Marais. Watching him closely from the public gallery on the defence side of the court were the other two industry experts (Mssrs. Kenneth Mundt and Bertram Price). Mr. Jack Siemiatycki sat ahead of the bar with the plaintiffs' team.

Marthinus Laurentius Neethling Marais

Laurentius Marais in 2000 testifying for the Bush Campaign

The voir-dire to qualify Mr. Marais did not take long. Mr. Guy Pratte (counsel to JTI-Macdonald, who is Mr. Marais' client in this case), gave a very slender introduction - in spite of or perhaps because of the technical difficulties that unusually hampered both sound and visual displays this morning.

Mr. Marais described his move from his home town of Stellenbosch in South Africa to the United States over 40 years ago, leaving for graduate studies in California. (Stellenbosch is coincidentally also the home of the Ruperts and their Rembrandt/ Rothmans empire).

Four decades of study (Stanford, mathematics and business), teaching (University of Chicago, Associate Professor) and consulting in the United States have erased all but small traces of the distinctive South African accent.

From his base in Wyoming, Mr. Marais has spent the past 20 years engaged by various industries in their litigation or regulatory work. He is a senior executive at William E. Wecker, which has a broad if frequently controversial clientele.

Mr. Pratte invited his witness to explain how it was that a statistician who had not published on lung diseases was in a good position to critique an epidemiologist.. "Applied statistical methods are at the core of what Dr. Siemiatycki attempts to do." And as for his experience in epidemiology, he curiously cited his work opposing legal claims by "haemophiliacs in the US who had become infected through medicines made from human plasma."

Although Mr. Pratte did not ask him about it, the most reported of Mr. Marais' consultancy experience is likely his work to support the Republican Party in the court review of the 2000 Florida vote. During that trial Mr. Marais was described by a lawyer for the Al Gore/Democratic Party as "a man who makes a living out of killing the testimony of other statisticians at the behest of evil interests."

Mr. Johnston, during his brief cross-examination on the voir-dire, also made a rare reference to the concept of evil. As he has done with other witnesses, he asked Mr. Marais to consider his testimony in light of the ethical standards set by his profession. (In this case the American Statistical Association, Exhibit 1697).

Statistical tools and methods, as with many other technologies, can be employed either for social good or evil. The professionalism encouraged by these guidelines is predicated on their use in socially responsible pursuits by morally responsible societies, governments, and employers. Where the end purpose of a statistical application is itself morally reprehensible, statistical professionalism ceases to have ethical worth.

Mr. Marais sounded a little confused about the existence of such a guideline, but did not shrink from the language. "As a general statement, I can't disagree with it," Mr. Marais said, adding that he felt that his work was consistent with that approach.

There was more confusion over how many times Mr. Marais had testified on behalf of tobacco companies. "Half a dozen to a dozen" times was his answer today. But when Mr. Johnston pointed out that ten years ago he said it was "10 to 15" times, he took refuge in statistics: "there's an overlap between those ranges!"

There was no dissembling about his views on causality, however. "I accept that it is a cause of many cancers, that it is a cause of cardiovascular disease and other respiratory diseases."  

At the request of Mr. Pratte, and with only a limp objection from Mr. Johnston, Justice Riordan qualified Mr. Marais as "an expert in applied statistics, including in the use of biostatistical and epidemiological data and methods to draw conclusions as to the nature and extent of the relationship between and exposure and its health effects." 

Mr. Marais' Expert Opinion

The dozens of expert opinions filed in this case are often a hundred or more pages long, and I confess that with the passage of time my memory is more than a little blurred. Nonetheless, I would hazard that Mr. Marais' (Exhibit 40549) is, with the possible exception of Mr. Duch, the most vitriolic and sharply worded of any of the defence critiques.

"This fundamental logical defect of the method as well as Dr. Siemiatycki' s flawed implementation of it-reasons ..."

"What Dr. Siemiatycki proffers is not a validated method .... It is, rather, an untested amalgam of statistical procedures that is incapable of producing statistically valid estimates"

"The estimates produced by Dr. Siemiatycki's method are fatally infected with the defects of the method and cannot be cured of them."

I noted that his oral testimony today was much less acidic. Perhaps it was the tone set by Mr. Pratte, whose trademark style seems rooted in the gentillesse of bygone times.  This courtly refinement seems a good match with Justice Riordan's expectations, and thus a good ground for Mr. Pratte to set as he prepared his witness to take aim at the Siemiatycky bulls-eye. 

One volley after another, Mr. Marais took aim.

Just as Mr. Siemiatycki had presented his conclusions in a step-by-step progression, Mr. Marais used a building-block approach to trying to dismantle his conclusion. His challenges were delivered in well-constructed full sentences, delivered at a judge-friendly slow pace.

Justice Riordan's contributions added to the tone of intense but respectful attention. His occasional questions over the day showed that he listening carefully but critically -- occasionally challenging Mr. Marais' characterization, or asking for clarification on subtle points.

There were a few clear patterns that seemed to emerge from these varying complaints. The flaws were fatal: for differing reasons, Mr. Siemiatycki's calculations could not be re-done to correct flaws or accommodate criticism. And the population-approach taken by the epidemiologist could not be reconciled with the statistician's understanding of the individual experience of smoking or getting sick.

Many arrows in his quiver

Mr. Marais may have agreed that "cigarettes caused disease," but he responded to Mr. Pratte's questions by distinguishing between "general causation" in a population, and "specific causation" in an individual. He frequently returned to the theme of assessing individual/specific harm as a barrier to accepting Mr. Siemiatycki's approach.

He said, for example, that there was no scientific basis to assess disease causation in an individual by appealing to a calculated "critical amount" of smoking beyond which the "probability was greater than 50%." 

In any event, Mr. Siemiatcyki's calculation of such a "critical amount"  had not been properly done. His meta-analysis had overlooked too much data. As a result, one could not say that any particular amount of smoking created a threshold limit to infer causation.

Mr. Siemiatycki had erred by lumping smokers together. There was too much "heterogeneity" in the population for averages to be appropriate. (The idea of an average seemed an unlikely anathema to this statistician!)

Mr. Marais introduced the concept of the wrongness of measuring the height of Quebecers, calculating the average height and then "assigning that average back to each individual member," a comparison he returned to over the day. 

Confidence intervals, or the lack of them, was another repeated criticism. The court was shown his "illustrative example" of how the confidence interval must not overlap a threshold value before one could safely conclude, on a balance of probabilities, that a statistical result could be inferred. 

If this had been properly taken into consideration by Mr. Siemiatycki, the critical amount for larynx   cancer would grow from 4 pack years to 25.

In addition to these "sampling error" concerns, Mr. Marais also found systematic (or non-stochastic) errors.

He said it was wrong to treat the four major types of lung cancer as a single disease. Individuals came with only one of those conditions, he pointed out.

He felt that the determination of the "critical amount" of smoking was one that was not "accurate" in statistical terms, and that therefore "anything that flows from it, like the calculation of the number of class members, inherits that problem." 

He acknowledged that pack-years was a frequently used metric, but did not think it properly measured intensity nor duration of smoking. He pointed to the different risk profiles of smokers who quit decades ago versus smokers who quit more recently, or who had not quit. "For smokers who quit by age 30 – even by age 35 – after 10 or 20 or 30 years, their level of risk for class diseases approaches that of people who never smoked." 

Nor can these groups be averaged. "There an be no person who personifies the average smoker. It is not possible for a person to be both a continuing current smoker and one who quit many years ago."

He felt Dr.Siemiatycki had erred when using a "multiplicative method" to consider combined risks (i.e. smoking and drinking, or smoking and being exposed to radon), instead of an "additive method." This second approach would increase the attribution to other causes (again HPV was cited!), while with multiplicative approaches "smoking always doubles the risk."  

By late afternoon, the criticisms were entering territories usually only occupied by the methodologically obsessed. Dr. Siemiatckyi had apparently erred in assigning "midpoints" when using a study whose results had been presented in ranges. And we are not done .... tomorrow Mr. Pratte will invite further criticisms from his witness.

Mr. Marais is scheduled to testify again tomorrow and Wednesday.