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Lawrence Martin, M.D., FCCP UHHS-Mentor 9000 Mentor Avenue Mentor, Ohio 44060 February 23, 2004
Letters to the Editor, Chest 3300 Dundee Road Northbrook, IL 60062-2348
As a reviewer for Chest, I am surprised the article by Ohar et. al. (1) was
published without closer analysis of the methods, and without editorial comment.
There is a national epidemic of asbestos litigation (2), with most of the mass
claims provably unfounded, and the mass claims process itself tainted by fraud
and unethical behavior (3-8). Unfortunately, the article by Ohar et al can only
harm attempts to bring objective diagnosis to these mass claims. Here are the
article's problems.
1) All asbestos subjects came from 3383 people in the "Selikoff registry,"
people recruited from "trade unions, television and newspaper
advertisements." In the Discussion section are we told that "subjects were
recruited from legal cases based on the presence of a radiographic
abnormality" and that this "could raise a question of potential selection
bias." The authors discount this bias by claiming the controls had >= 10
years' observation without radiographic progression. Yet the controls
were merely a subset (243) of the 3383 people solicited for the registry;
this left 3140 people diagnosed -- because of some abnormality on chest x-ray -- with "asbestos-induced lung disease."
A subset of the original cohort is not a true control group. A true control
group would be another 3000+ chest x-rays from a similar demographic
group (age, sex and smoking history) without an asbestos exposure history.
Chest x-rays of true controls would be mixed randomly along with the
Selikoff registry chest x-rays, so that all 6000+ films could be read blindly.
Furthermore, given interobserver variation among B-readers (9), an
epidemiologic study based on x-rays should include at least three B-readers, each of whom must be blinded completely to the subjects'
background.
2) The study omits possibility that some of the Selikoff registrants don't have
asbestos-related disease. It is noteworthy that 74% of the asbestos subjects
had an ILO score < 1/1, i.e., 1/0 or lower. There is now a substantial
literature showing that a profusion reading of 1/0 is completely non-specific for diagnosis of interstitial lung disease, as it may be related to
smoking history, aging, heart disease, and other non-fibrotic conditions
(10-14). In fact, a recent article in Chest states: "the chest radiograph
should not be used as the sole diagnostic tool as it will be wrong more
often than it will be right." (14) It is inconceivable that not a single
Selikoff registry subject had some other cause for small opacity profusion
than asbestos.
3) The authors state that "pleural abnormalities were the only abnormality in
54% of subjects with low ILO scores." Yet it is well known that pleural
abnormalities can be difficult to both diagnose on plain x-ray and attribute
as to causation (15). For example, there are numerous causes of pleural
shadows unrelated to asbestos, e.g., prior thoracic surgery, old
inflammatory disease, healed rib fractures, obesity (pseudo pleural
thickening), etc. (13, 15-16). It is inconceivable that not a single Selikoff
registry subject had some other cause for pleural abnormality than
asbestos.
4) Sixty-seven subjects (out of 3140 with "asbestos disease") had lung
cancer, and only 1 of these was a never smoker. Yet all 67 cases of lung
cancer were accepted by the authors as "asbestos-induced" (the article's
title). There is considerable debate in the literature about the role of
asbestos in causing lung cancer in the absence of true asbestosis (17-20),
which for reasons already presented is not documented in this cohort.
A result of these errors is the unwarranted assumption that 92.7% of this cohort
recruited for litigation purposes have asbestos-induced disease. This statistic flies
in the face of clinical experience, and of anything published in the medical
literature. It is even higher than the 60-80% positive diagnosis rate found when
plaintiff attorneys pay for the B-reader reports! (8; page 86). In fact, objective
review of asbestos diagnoses in these attorney-sponsored mass claims (of which
the Selikoff registry is part) has shown mis-diagnosis in the vast majority of cases
(8, 13, 21)
In epidemiologic studies like this one, unless all subjects are evaluated in a
completely blinded fashion, the results can become self-fulfilling. As with B-readers who are paid for positive results by plaintiff's lawyers (5-8), the authors
have assumed the diagnosis before it has been proven. The authors' basic
conclusions -- that there is a changing pattern of asbestos-induced disease, and
that "an augmented number of new cases of asbestos-induced lung disease may be
anticipated in the next two decades" - are not only completely unfounded, but
feed right into the plaintiff lawyers who developed the now discredited asbestos
screening process. It seems no coincidence that this work, with its lack of true
controls and unwarranted conclusions, was funded by the Selikoff registry.
Perhaps the authors are unaware of the Alice-in-Wonderland nature of mass
asbestos litigation, or of the growing list of publications that has undermined its
validity (2-16). Chest's review process should have been aware, caught the
manifest conflict of interest as well as the illogical results, and at least published
an editorial response.
The authors no doubt intended their study to be fair and valid, but intentions are
not enough. The horrible quagmire of mass asbestos litigation mandates that
epidemiologic studies on asbestos diagnosis be 100% blinded and include real
controls (22), and that they in no way be funded by any source connected with
plaintiff's attorneys. Without those protections against bias and illogic, the results
can never be accepted as scientifically valid, no matter where they are published.
Lawrence Martin, M.D., FCCP Associate Professor of Medicine Case University School of Medicine Phone: 440-974-4442 Fax: 440-964-4273 E-mail: larry.martin@adelphia.net
References
2. Carroll S, Hensler D, Abrahamse A, Gross J, White M, Ashwood S, Sloss E.
Asbestos Litigation Costs and Compensation: An Interim Report. RAND Corp,
Santa Monica, CA, 2002. 3. Parloff R. The $200 billion miscarriage of justice. Fortune, March 4, 2002;
145:154-8.
4.
Taylor S, Jr. Greedy lawyers cheat real asbestos victims. The Atlantic Online.
5.
Egilman D. Asbestos screenings. Amer J Indust Med 2002;42:163.
6. Setter DM, Young KE, Kalish AL. Asbestos: Why we have to defend against
screened cases. Mealey's Litigation Report, November 12, 2003;18:1-16.
7. Bernstein DB. Keeping junk science out of asbestos litigation. Pepperdine
Law Review, Volume 31, No. 1, 2004; 11-28.
8. Brickman L: On the Theory Class's Theories of asbestos litigation: Disconnect
between scholarship and reality. Pepperdine Law Review, Volume 31, No. 1,
2004; 33-170.
9. Ducatman AM, Yang WN, Forman SA. 'B-Readers' and asbestos medical
surveillance. J Occup Med 1988; 30:644-647.
10. Weiss W. Cigarette smoking and small irregular opacities. Br J Indust Med
1991; 48:841-844.
13. Reger RB, Cole WS, Sargent EN, Wheeler PS. Cases of alleged
asbestos-related disease: a radiologic re-evaluation. J Occup Med 1990;
32:1088-90.
16. Lee YC, Runnion CK, Pang SC, de Klerk NH, Musk AW. Increased body
mass index is related to apparent circumscribed pleural thickening on plain chest
radiographs. Am J Ind Med 2001 39:112-6.
17. Browne K. Is asbestos or asbestosis the cause of the increased risk of lung
cancer in asbestos workers? Brit J Indust Med 1986;43:145-149.
18. Jones RN, Hughes JM, Weill H. Asbestos exposure, asbestosis, and asbestos-attributable lung cancer.
Thorax 1996;51:S9-S14.
21.
Houser PG: Affadavit in Manville Personal Injury Settlement Trust Medical
Audit Procedures Litigation, 98 Civ. 5693, March 13, 1999, p. 9; quoted in
Carroll S, Hensler D, Abrahamse A, Gross J, White M, Ashwood S, Sloss E.
Asbestos Litigation Costs and Compensation: An Interim Report. RAND Corp,
Santa Monica, CA, 2002.; page 20.
22. Martin L. Runaway Asbestos Litigation -- Why it's a Medical Problem http://www.mtsinai.org/pulmonary/Asbestos/AsbestosEditorial.htm |