Apportionment: Science or Science Fiction?

Saturday, November 4, 2006 | 0

By Marjory Harris

In the first article in a series of editorials on "Workers' Compensation Disabled: What Went Wrong on the Road to Reform?" we explore the legal and scientific underpinnings to the current concept of apportionment of permanent disability. We look at common logical fallacies we have found in reports, deposition transcripts and case law, and how to overcome these with research and specific questions. We propose a method for evaluating apportionment -- IPECAC -- similar to the IRAC method we used in law school -- and provide a downloadable guide you can print out and take to any apportionment deposition.

Like the last set of reforms in 1989, SB 899, signed into law on April 19, 2004, was meant to reduce litigation and get the lawyers out of the system. One of its most unlikely assumptions was that a physician could divine what percentage of permanent disability was the direct result of the industrially-caused condition or its side effects, as opposed to "other factors." This has led to endless litigation in the "apportionment wars."

In this article we discuss the science and the fiction behind Labor Code Section 4663.

At the unveiling of the new Section 4663, there was considerable speculation about what "other factors" meant, and whether one could apportion to asymptomatic pathology. In the more than two years since SB 899, there has been only one significant legal opinion on this issue, the Escobedo case. It opens the door to many more questions than answers. It requires opinions by both physicians and workers' compensation judges. On pages 2 and 3 of the opinion, the Commissioners set forth 5 holdings.

Escobedo v. Marshalls (2005) 70 Cal. Comp. Cases 604 (Appeals Board en banc opinion), pet. for rev. den. sub nom. Escobedo v. W.C.A.B. (2005) 70 Cal. Comp. Cases 1506 (writ denied).

1) "Causation" in L.C. 4663(a) refers to the causation of the permanent disability, not causation of the injury.

2) Both a reporting physician and the WCAB must make determinations of what percentage of the permanent disability was directly caused by the industrial injury and what percentage was caused by other factors.

3) The applicant has the burden of establishing the percentage of permanent disability directly caused by the industrial injury, and the defendant has the burden of establishing the percentage of disability caused by other factors.

4) Apportionment caused by "other factors both before and subsequent to the industrial injury, including prior industrial injuries," may include not only disability that could have been apportioned prior to SB 899, but it also may include disability that formerly could not have been apportioned (e.g., pathology, asymptomatic prior conditions, and retroactive prophylactic work preclusions), provided there is substantial medical evidence establishing that these other factors have caused permanent disability.

5) Even where a medical report "addresses" the issue of causation of the permanent disability and makes an "apportionment determination" by finding the approximate relative percentages of industrial and non-industrial causation under section 4663(a), the report may not be relied upon unless it also constitutes substantial evidence.

The Escobedo board recited some rules for the substantial evidence requirement: "a medical opinion must be framed in terms of reasonable medical probability, it must not be speculative, it must be based on pertinent facts and on an adequate examination and history, and it must set forth reasoning in support of its conclusions."

"Substantial evidence" "if true, has probative force on the issues. It is more than a mere scintilla, and means such relevant evidence as a reasonable mind might accept as adequate to support a conclusion. It must be reasonable in nature, credible, and of solid value.'" Braewood Convalescent Hospital v. WCAB (1983) 34 Cal.3d 159, 164.

Legal Fiction: Doctors can assign percentages of causation

Science Fiction: It sounds true at first light, but like a mirage, is a lie by noon, to paraphrase Hemingway. As I read the apportionment paragraphs of forensic reports, I usually find no substance to support the percentages.

In the common law tradition, legal fictions are suppositions of fact taken to be true by the courts of law, but which are not necessarily true.

Are physicians scientists? Their observations are usually documented only in individual charts, not as studies across their practice. Thus, they are anecdotal observations, not meeting the scientific requirements of reliability, validity and rigor.

It is the legal advocate's duty to insist on rigor (the quality of being logically valid) in forensic reports. This requires close analysis of the facts of the case, medical research, and clearly worded explanations. If the physician does not do this, the burden shifts to the lawyer to formulate the correct analysis and to pose carefully worded questions.

Use the IPECAC method as an outline or checklist (see below)

The Scientific Method: Seeking Reliability, Validity and Rigor

The scientific method is a body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting and integrating previous knowledge. It is based on observable, empirical, measurable evidence, and subject to laws of reasoning. All such evidence is collectively called scientific evidence. Wikipedia http://en.wikipedia.org/wiki/Scientific_study

Evidence-based medicine (EBM) applies the scientific method to medical practice. According to the Centre for Evidence-Based Medicine, "Evidence-based medicine is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients." http://en.wikipedia.org/wiki/Evidence_ based_medicine

Apportioning to Epidemiological Studies -- the Camel's Nose Intrudes into the Tent

There are various good arguments against allowing apportionment to epidemiological traits. There is, of course, the "eggshell skull" doctrine that one takes the victim as one finds him or her. There are the anti-discrimination statutes of the State and Federal governments. And then there is science. While the various types of epidemiologic studies are a valuable tool for science, in identifying what to study further, where to invest limited resources, and the like, such studies rarely apply to everyone. We need to focus on the individual whose benefits are being diminished and ask how probable is it that genetics or other epidemiologic factors played a role in causing the permanent disability not in the population being studied, but in this particular worker?

And in fairness, we need to assume that this worker could be one of those who do not have the problem being studied, unless there is other proof beyond mere statistics.

"Epidemiology is the scientific study of factors affecting the health and illness of individuals and populations, and serves as the foundation and logic of interventions made in the interest of public health and preventive medicine. It is considered a cornerstone methodology of public health research, and is highly regarded in evidence-based medicine for identifying risk factors for disease and determining optimal treatment approaches to clinical practice.

Strictly speaking, epidemiology can only go to prove that an agent could have caused but not that, in any particular case, it did cause: "Epidemiology is concerned with the incidence of disease in populations and does not address the question of the cause of an individual's disease. This question, sometimes referred to as specific causation, is beyond the domain of the science of epidemiology. Epidemiology has its limits at the point where an inference is made that the relationship between an agent and a disease is causal (general causation) and where the magnitude of excess risk attributed to the agent has been determined; that is, epidemiology addresses whether an agent can cause a disease, not whether an agent did cause a specific plaintiff's disease." http://en.wikipedia.org/wiki/

Epidemiology

Remember IRAC?

Issue

Rule

Application

Conclusion

I have created the "IPECAC" method for analyzing apportionment issues:

IPECAC Method

I -- Issue (Is there any percentage of permanent disability attributable to factors other than the industrial injury?) If yes, go to the next step.

P -- Premise (what is the physician's premise for apportionment to non-industrial factors?)(e.g., obesity causes knee problems -- epidemiologic risk factor)

E -- Erudition, or knowledge acquired through study and reading, and Evidence. This is a requirement of the new paradigm of "evidence-based medicine" (EBM). Anything less is anecdotal and likely the "ipse dixit" logical fallacy.

C -- Causal relationship and the weighing of counter evidence: Even if there is EBM to support the premise, is there evidence that does not support the premise? In other words, does the EBM show cause and effect or simply correlation? If not dispositive of the issue, proceed to the next step (do studies show that all obese people have knee problems? Or that if bones are malaligned, obesity then causes problems?)

A -- Application or Analysis: how does this relate to the facts of this case and this injured worker? Connect all the dots! ("This IW has obesity and malaligned bones").

C -- Conclusion re: causation. Is the conclusion logically derived from the premise, the erudition and evidence, the weighing of causes and counter evidence, and the facts of the instant case? If not, examine further for logical fallacies, contrary studies, and legal attacks based on case law, other laws such as FEHA, concepts of fairness, Labor Code Section 3202, etc. and the like.

IPECAC for analyzing apportionment:

Issue

Premise

Erudition & Evidence

Causal Relationship & Counter Argument

Application & Analysis

Conclusion re: Causation

Click here to download a chart to take with you to depositions. It summarizes IPECAC and includes questions to support or refute apportionment.

"If She Sinks, She's Not A Witch": Spotting Logical Fallacies Used to Support Apportionment

It was just a few hundred years ago that trial by water, or the swimming of witches, was used to determine if the defendant was a witch. "It was believed that water rejected servants of the devil and that if a suspected person floated and refused to sink when placed in water it was proof of guilt." That it might be proof that the person knew how to float or doggy paddle or even swim, or that the person was being kept afloat by those who held onto the ropes, seems not to have been considered. While the logical fallacy that supported the "indicium aquae" seems patent today, the logical fallacies supporting much of the apportionment paragraphs in our medical- legal reports may be harder to spot.

The usual report has something like this: "The patient's MRI indicates degenerative changes in the lumbar spine. I estimate approximately 50 percent of her current disability can be apportioned to preexisting degenerative disc disease and spondylosis and approximately 50 percent can be attributed to her work activities of frequent heavy lifting." No explanation is given, no studies cited. In fact, the studies that are available do not support this opinion. This is the "ipse dixit" fallacy, that it is true because the doctor says so.

Ipse dixit violates Escobedo: "The opinion of the expert is no better than the reasoning upon which it is based." If there is no reasoning, there is no substantial evidence.

If the doctor insists that his or her own experience is sufficient, remind him/her of this: "The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research." (Sackett DL, Straus S, Richardson S, Rosenberg W, Haynes RB. Evidence-based Medicine: how to practice and teach EBM, ed 2. London: Churchill Livingston, 2000.) Ask what "external clinical evidence from systematic research" supports his or her view.

Here is one that apportions to post-injury inability to exercise, leading to weight gain, in someone who worked on her feet all day before the work injury: "As far as apportionment is concerned, I recommend that disability be apportioned 25% to her underlying degenerative disk disease, 25% to her exogenous obesity (which is a significant factor in her failure to improve), and 50% to the incident on February 25, 2004." No explanation is given, another "ipse dixit" and adding a "false cause."

Converting causation of injury into causation of permanent disability -- not allowed by Escobedo: While alcohol consumption may have played a role in causing avascular necrosis, if the afflicted bone is removed and the residuals are due to a joint replacement, then the cause of the injury has nothing to do with the cause of the permanent disability. "Here, we conclude that there is no basis for apportionment of applicant's permanent knee disability. Dr. Isono reported that applicant's need for right knee replacement surgery was caused by various factors, including industrial and non-industrial factors. However, medical treatment is not apportionable. (Granado v. Workmen's Compo Appeals Rd. (1968) 69 Ca1.2d 399 [33 Ca1.Comp.Cases 647].) Moreover, despite the various causes for the knee replacement surgery, applicant's work limitation to semi-sedentary work, according to Dr. Isono, is due to the knee replacement and the symptoms related to the prosthesis. Thus, while we held in Escobedo v. Marshalls, supra, that apportionment of permanent disability under section 4663(a) may be based on any "other factor", here there are no "other factors" that caused permanent knee disability. Rather, the permanent knee disability was caused by the knee replacement and the symptoms associated with the prosthetic knee replacement. Therefore, under section 4663 and Escobedo V. Marshalls, supra, we conclude that there can be no apportionment of applicant's permanent knee disability in these matters." Board panel decision, Steinkamp v. City of Concord, issued March 30, 2006, writ denied.

Confusing orthopedic permanent disability with psychiatric permanent disability: The defense QME opines, "I know this is very complicated. I would like to be sure that this is all as clear as possible. To summarize: Dr. [AQME] and I basically agree that about 30% of Ms. IW's permanent psychiatric disability is non- industrial, period. This 30% is attributable to factors that have nothing to do with her work at [hospital], regardless of any orthopedic disputes. The issue is that the remaining 70% of psychiatric disability changes, depending on which orthopedic opinion is accepted. The more orthopedic disability that is ultimately found to be of non-industrial cause, the more Ms. IW's psychiatric disability (resulting from chronic pain and so on) is likewise non-industrial. To the extent that permanent orthopedic disability is attributed to one industrial injury or the other, there is correspondingly more permanent psychiatric disability attributable to that injury."

Huh? If 70% of the psychiatric permanent disability is caused by the effects of the industrial injury, why would it be further changed by looking at the percentage of causation of the permanent disability related to the industrially-caused orthopedic injuries? This could turn into an endlessly shifting algorithm. Is this the red herring fallacy? Sure seems smelly.

Does not meet Escobedo: "Absent that underlying pathology, he would be better off today or to put it another way, his underlying pathology has contributed to his disability." Panel majority found this insufficient to support apportionment as it failed the "how and why" test of Escobedo, since there was no explanation given for why applicant would be better off had it not been for the underlying pathology. Wood v. SCIF: 34 CWCR 15 (2005)

Does meet Escobedo: "With regard to apportionment, Dr. Levin concluded that 50 percent of Applicant's disability was related to her pre-existing underlying degenerative arthritis. In a subsequent report, Dr. Levin opined that Applicant's disability could be attributed to the chondroplastic surgery performed by Dr. Kingsley, which consisted of shaving the articular surface of Applicant's lateral femoral condyle and tibial plateau and would be necessary for osteoarthritis but not for a simple tear of the meniscus. He concluded that the level 9 or 10 disability described by Applicant in her deposition was much more consistent with her pre-existing osteoarthritis than with a tear of the meniscus and its resection." Beery v. WCAB, 70 Cal. Comp. Cas 1334 (2005)

How to Smoke Out Bogus Apportionment: Some Key Questions

Although apportionment is an affirmative defense and the burden is on the defendant to prove apportionment (see Escobedo and Labor Code Section 5705), it may be risky to leave it unchallenged, unless no explanation whatsoever is given for the apportionment percentage. Otherwise, one needs to probe for legal and medical underpinnings.

First, examine the language used by Dr. Ovadia in Escobedo: "Although denying any prior problems with her knees, it is medically probable that she would have had fifty percent of her current level of knee disability at the time of today's evaluation even in the absence of her employment at Marshalls." This passed the Escobedo tests because 1) there is medical probability and 2) the pathology would have caused ratable disability at the time of the evaluation even in the absence of a work injury.

The law makes a legal distinction between "possibility" and "probability." Opinions based upon possibility are not necessarily admissible. Therefore, if the doctor uses any of the following phrases in connection with his or her opinion, such testimony may be stricken by the judge: (1) It "might be" true. (2) It "is possible." (3) It "might have" that effect. (4) It "could have" that effect.

To refute apportionment to preexisting, asymptomatic pathology, inquire along these lines:

How and why does the pathology described result in X% of IW's permanent disability at the time of his evaluation? As to "pathology," on what evidence do you rely that there was pathology pre-existing the industrial injury or occurring due to non-industrial factors after that injury?

What specific scientific studies or literature are you relying on?

You have referred to epidemiologic studies as showing that X can cause Y, but can you say with reasonable medical probability in this case that X caused Y?

Did the industrial injury light up the underlying asymptomatic degenerative disc disease to make IW symptomatic?

Do-It-Yourself Medical Research: Some Useful Links

Since revised Labor Code Section 4663 went into effect, I have seen very few citations to scientific studies in reports received from Medical Evaluators, despite a request in my letters such as this: "If you apportion to pre-existing asymptomatic pathology or risk factors such as age or obesity, please state in detail the scientific underpinnings for your opinion. What journal articles or other evidence of scientific studies support your conclusions?"

Don't leave it to the doctors to do the medical research! There is a great deal of information online. Google is a good place to start in order to get general information on the diagnosed condition and its causes.

Insist that the physicians document their opinions with medical citations, just as lawyers have to do when they give legal opinions.

Don't leave it to the doctors to do the medical research!

"PubMed": "a service of the U.S. National Library of Medicine that includes over 16 million citations from MEDLINE and other life science journals for biomedical articles back to the 1950s. PubMed includes links to full text articles and other related resources.

Ex.: Search for "osteoarthritis with trauma with obesity with knee" yielded 38 hits

Wheeless' Textbook of Orthopaedics
http://www.wheelessonline.com/

The Med Engine:
http://www.themedengine.com/ index.html

Medscape:
http://www.medscape.com/home

Evidence-based Medicine ("EBM"):
http://www.herts.ac.uk/lis/subjects/ health/ebm.htm This UK site has many useful links.

getMedLegal.com's Medical Links:
http://www.getmedlegal.com/wclaw/ lists.html#med

Harris has been practicing law since 1974, and is a State Bar Certified Workers' Compensation Specialist. She first practiced workers' compensation law on the defense, then became an applicants' attorney. She appears at the San Francisco and Oakland WCABs. She also has a solid background in civil litigation, arbitration, and business law. Harris can be reached at (510) 558-1580 or by e-mail to MHarrisLaw@earthlink.net

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The views and opinions expressed by the author are not necessarily those of workcompcentral.com, its editors or management.