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Industrial
Causation to Injury, Disability and Evidence-Based Medicine
by Michael McDonald
In this series, Michael G. McDonald,
Esq. of the McDonald Law Corporation offers practical advice to WC
lawyers and adjustors.
Causation, what is it? It is not a word customarily used in newspapers
or on the street. It is a term of art in workers’ compensation
determining the liability of an employer for injury under Labor Code
§3600(a) and apportionment of permanent disability under Labor
Code §§4663 and 4664.
Evidence-based medicine (EBM), how is it used and when should it be
used in our California workers’ compensation system?
Causation and Industrial Injury
It has long been held that employment and an industrial injury must
be linked in some causal manner. The causal connection between the
employment and the alleged injury need not be the sole cause of the
injury. However, the connection must be a contributory cause of the
injury. Maher v. WCAB (1983) 48 CCC 326.
This theory encompasses situations such as idiopathic seizures and
falls. The leading case on point is Employers Mutual Liability
Ins. Co. of Wisconsin v. IAC (Gideon) (1953) 18 CCC 286. In that
case, the defendant was found liable for injuries sustained from hitting
the ground at work, even though the applicant’s seizure was
not industrial. The issue was what injuries did the applicant suffer
from the fall?
There are many instances where we, defendant and applicant advocates,
request a doctor for an expert opinion on whether an incident caused
an injury. Recently, I had a well-known AME tell me at deposition
that a four year old incident (a fall) which caused no injury or impairment
two years after the incident, now resulted in a low level of permanent
disability to the hip and the need for a potential hip replacement.
When asked how he arrived at that conclusion in light of the fact
that all tests were negative two years prior, the AME advised that
it just made sense to him. Were there tests which could be performed
to determine whether the present condition was non-industrial? Yes,
bone scans and blood tests could be used. This was important information
since the applicant had other significant arthritic issues to other
body parts which had been diagnosed as hereditary and pre-existing.
As advocates for our clients, we need to challenge the “experts”
to support their opinions with the use of evidence-based medicine
methods and relevant facts. It has long been held that medical opinions
superseded by more reliable medical opinions are insufficient. Jones
v. WCAB, (1968) 33 CCC 221. Where a physician fails to examine
the worker, but bases an opinion on review of other medical histories,
the opinion is not substantial evidence. Sweeney v. WCAB
(1968) 33 CCC 404. Contra, Bethlehem Steel Corp. v. WCAB
(Compani) (1982) 47 CCC 1283 (writ denied).
If an expert’s opinion is based upon incorrect legal theories
or does not rely upon relevant facts, the opinion is not substantial
evidence. Bracken v. WCAB (1989) 54 CCC 349.
Evidence-Based Medicine
EBM really came into the limelight in California with the adoption
of SB 238 and AB 227 in 2004. Up until that time, the WCAB typically
utilized the “years of experience” theory or the “because
I said so” theory of the doctor to support a finding. These
theories are still expressed by many of our hearty medical examiners
to support their opinions. Now, we see the use of EBM through ACOEM,
Utilization Review and Official Disability Guidelines (ODG).
Although the above-referenced guidelines are utilized for treatment,
EBM can be used to analyze causation of injury, as well as apportionment
of permanent disability.
An EBM analysis requires a review of the factual evidence; review
of the epidemiologic data to support a relationship with industrial
causation; evidence of industrial exposure; and review of other relevant
factors.
Is there evidence of disease? Is the diagnosis correct? Does the evidence
support the diagnosis? These questions need to be asked of our experts,
especially if there is a conflict in the medical record.
What epidemiologic data/evidence exists for the disease or condition?
Do the data support a relationship with work? Again, what outside
resources has the medical examiner reviewed to support the expert
opinion? Is the scientific evidence reliable? Is there empirical testing?
Is it peer-reviewed? What is the known or potential error rate in
the operation standards? Is there a general acceptance of the data/theory/technique
in the scientific community?
What predominantly objective evidence exists to support the level
of occupational environmental exposure which could cause the disease?
What are the frequency, intensity and duration of the exposure? Where
did the expert get the information?
What other relevant factors are present in the case? What individual
risk factors other than occupational exposure exist? Could those risk
factors contribute to the development of the disease or condition?
Finally, the practitioner needs to question the expert on what conflicting
evidence, if any, exists which suggests the assessment is inaccurate?
The practitioner needs to have specific facts available to question
the expert at deposition. Further, many of our experts typically set
aside up to two hours for deposition. The questions relating to EBM
may require much more additional time, especially if the goal of the
deposition it is to discredit the expert’s opinion.
Keep in mind that the manner in which the expert provides an opinion
not only determines whether the opinions are adequate, but whether
the opinions are persuasive. People v. Bassett (1968) 69 C2d
122.
Causation of Permanent Disability/Apportionment
Apportionment limits the liability of the employer for an injured
worker’s permanent disability. Employers must compensate injured
workers only for that portion of permanent disability attributable
to a current industrial injury, not prior injuries or non-industrial
factors. Brodie v. WCAB (2007) 72 CCC 565; LC 4663, LC 4664.
Escobedo v. Marshalls (2005) 70 CCC 604 (en banc) requires
consideration of the cause of permanent disability. Examiners are
required to make an apportionment determination by finding the approximate
percentage of the permanent disability caused by the direct result
of the industrial injury, as well as other causative factors before
and after the industrial injury. The opinion must be framed in terms
of reasonable medical probability, must not be speculative, and must
be based upon pertinent facts, adequate examination and history. The
examiner must explain the how and why of the apportionment opinion.
The courts have validated the Escobedo analysis. See Andersen
v. WCAB (2007) 72 CCC 389; SCIF v. WCAB (Echeverria)
(2007) 72 CCC 33; E.L. Yeager Construction v. WCAB (Gatten)
(2006) 71 CCC 1687.
The practitioner needs to review the causative source of an injured
worker’s disability and determine whether the medical expert’s
opinion does not merely pay lip service to Escobedo, but actually
follows the analysis. The physician must analyze the reason for the
disability.
For instance, in osteonecrosis cases, the medical expert must determine
whether the condition was pre-existing and a causative source of the
current disability. In other words, the reason for the disability,
including pain and limitations resulting from hip replacement, is
a factor to be considered in the apportionment determination. See
Malcolm v. CNA Ins. Group (2008) 36 CWCR 176.
This approach may be used in any number of cases. In all cases, EBM
should serve as the basis for analysis. In cases of degenerative disc
disease for instance, what x-ray evidence indicates the existence
of the disease process? What individual risk factors exist which contributed
to the disease process? How long has the disease process existed?
Were there any post-injury factors which could have been a contributor?
If so, what factors exist?
Conclusion
Our disability system for injured workers has changed. We need to
change with it. Whether one represents the injured worker or the employer,
we need to focus our efforts for clear, persuasive and substantial
reports by utilizing EBM tools, such as ACOEM, ODG and UR opinions.
Whether to use an Agreed Medical Evaluator (assuming the AME will
split the baby on causation of injury and apportionment) is a topic
for another day.
Today, however, we deal with Labor Code §4663(a): Apportionment
of permanent disability shall be based on causation. This requires
an analysis of the causal factors of that disability.
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About the Author:
Michael G. McDonald is the founder of McDonald Law Corporation in Concord,
California and a Certified Specialist in Workers' Compensation Law, State
Bar of California. He is a Director for the California Workers’ Compensation
Defense Attorneys Association.
Michael G. McDonald, Esq.
McDonald Law Corporation
1800 Sutter
Street, Suite 430
Concord, CA 94520-2563
Voice: (925) 363-4380
Fax: (925)
363-4352
Other locations: Sacramento, San Jose and Fresno www.mcdonaldlawcorp.com
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