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Revisiting “Preexisting Conditions,” “Major Cause” And Other Terms Used In Workers’ Comp Cases

If your patient has a work-related injury or an occupational disease, it is important for you to understand the current definition of “pre-existing condition.” This requires an understanding of a number of key terms used in workers’ compensation cases.

The revised definition of “pre-existing condition” became effective January 1, 2002. Even though it has been in effect for over three years, it and related concepts are well worth revisiting. This article is based in part on our report in the Summer/Fall 2002 edition of the Medical-Legal Journal, Vol. 22.

A “preexisting condition” is a medical condition which existed before the worker’s claimed work injury or occupational disease and had a part in causing it. Preexisting conditions must be considered in determining whether the workers’ compensation claim is compensable.

Definitions
As to both injuries and occupational diseases, the core definition of preexisting condition is:

Any injury, disease, congenital abnormality, personality disorder or similar condition that contributes to disability or need for treatment…

Some aspects of the definition of preexisting condition vary depending on whether your patient has an “injury” or an “occupational disease.

An “injury” usually results from a one-time, discrete injurious event (a work-related accident).

An “occupational disease” occurs gradually over time. An occupational disease may be the result of a series of traumatic events or occurrences; or repeated/prolonged exposure to dust, fumes, vapors, gases, radiation or other substances. A mental disorder may also be an occupational disease.

Injuries and Preexisting Conditions
In injury claims, there must have been a diagnosis of or medical treatment for the symptoms of the preexisting condition before the claimed work injury, except where the alleged preexisting condition is arthritis or an arthritic condition.

So, medical records showing diagnosis or treatment of the preexisting condition before the claimed work injury are needed in all injury cases, except when the preexisting condition is arthritis or an arthritic condition.

Note that while arthritis is excepted from the requirement of having been diagnosed or treated prior to the injury claim, apparently by definition it still must be shown to have “preexisted” the claimed injury.

In injury claims, a medical condition which only made the worker more susceptible to the injury is not a preexisting condition. That is, if a prior condition only predisposed the worker towards the injury and did not actually contribute causally to the injury, then the condition does not meet the definition of “preexisting condition.”

Occupational Diseases: How the Preexisting Condition Definition Differs
As to occupational disease claims, the preexisting condition must precede the onset of the claimed occupational disease, or precede the claim for worsening of an occupational disease.

In occupational disease claims, several of the restrictions pertaining to the definition of preexisting conditions for injuries do not apply. The prior diagnosis and treatment requirements and the arthritis exception do not apply to occupational disease claims. Also, the “more susceptible” limitation does not apply to occupational disease claims, only to injuries. That is, medical conditions rendering a worker more susceptible to an occupational disease, and those for which pre-onset diagnosis and treatment have not occurred may qualify as “preexisting conditions” to claimed occupational diseases.

WHY ARE PREEXISTING CONDITIONS IMPORTANT?

Proving Injuries
In an injury claim, the worker need only show that the work accident (injurious incident) was a material cause of the claimed injury, in order to prove a “compensable injury.” That is, if the work incident was a material factor in causing the claimed injury, the injury claim is compensable. A material factor is only a significant factor; it need not be 50%, or necessarily close to it.

However, if at any time, the compensable injury combines with a preexisting condition so as to cause or prolong disability or need for treatment, then the worker must prove that the compensable injury was/is the major contributing cause of the disability or need for treatment of that combined condition, in order for the combined condition to be compensable. “Major contributing cause” means over 50% of the cause.

In other words, once a preexisting condition enters the picture, the worker’s burden of proof increases from “material cause” to “major cause.”

The “burden of proof” refers to which party in a dispute has the responsibility to present evidence to prove a particular point.

Employer’s Burden
To determine whether the worker will have to meet this increased causation standard, which may jeopardize his/her comp coverage, the first question is: Was there a preexisting condition? If so, then second: Did the preexisting condition combine with the compensable injury?

These questions are the employer/insurer’s burden. The employer/insurer must prove there was a preexisting condition and that it combined with the compensable injury. The employer/insurer has these “burdens of proof.”

Worker’s Burden
Once this combined condition is established, then the worker has the burden to prove that the original compensable injury is the major contributing cause of the disability and/or the need for treatment of the combined condition.

Your Opinion
As treating physician for the injured worker, you will be asked to give your opinion at all levels of inquiry:

  1. Was there a preexisting condition? If so, what was it?
  2. Did the preexisting condition combine with the compensable injury? (Be sure you know what the compensable injury was); and, finally,
  3. What is the major contributing cause of the disability and/or the need for treatment of that combined condition — the pre-existing condition or the compensable injury?

Should You “Just Say Yes” to the IME?
Of course, the employer/insurer will make these questions easy for you by simply asking if you agree with the report of the “independent” medical examiners (IME) they hired. The IME doctors probably concluded there was a preexisting condition which combined with the work injury, and the preexisting condition is now the major cause of the disability and/or need for treatment. Simply check the box, sign the form and return, if you agree.

Be careful. If you say you agree, that means you agree with everything in the IME report. Your endorsement lends the weight of your opinion as treating doctor to all the conclusions (and legal implications) of the IME report. That is, if the IME doctors opined that a preexisting condition (which combined with your patient’s injury) is the major cause of his/her current need for treatment, your endorsement will certainly result in the termination of your patient’s workers’ compensation coverage. This result will be almost impossible to turn around.

Carefully review the IME report submitted to you. If you disagree, explain fully in writing each point of your disagreement.

Your explanation of your points of disagreement should reflect your knowledge of:

  • the mechanism of the work incident causing the original injury,
  • the alleged preexisting condition,
  • all the available medical records including diagnostics and treatment records on the injuryand the preexisting condition,
  • all other potential causes and their relativecausal contribution, and
  • the reasons why your opinion on the cause ofyour patient’s current condition is correct, asopposed to that of the IME doctors.

If you need any additional medical records or other information, your patient’s attorney should be able to help you. Your well-reasoned explanation will insure that the judge has complete information on which to base his/her decision. (For more information, see “Do You Really Agree with that ‘Independent Medical Exam’?” Medical-Legal Journal, Vol. 15, Spring 2000.)

Consequential Condition – another situation where an injury claim requires a major cause opinion.
Your patient may suffer an injury or disease as a consequence of his/her compensable injury. If so, your patient will need your medical opinion to prove by medical probability that the original compensable injury is the major cause of this consequential condition.

In summary, as to work injuries, major cause is the standard of proof only if the compensable injury combined with a preexisting condition or there was a consequential condition.

A Typical Scenario
At this point, it would be helpful to flesh out all these abstractions. Here is a typical scenario:

The worker hurts his back bending and lifting on the job. The bending and lifting was at least a material factor causing the worker to go to the doctor (and/or take off work) for his back. The employer accepts “low back strain,” as a compensable work injury.

As symptoms persist and treatment continues, a disrupted disc is discovered.

The referrals and diagnostics necessary to discover the disrupted disc were the result of ongoing, unsuccessful attempts to treat the low back pain the worker has suffered since the work injury.

The employer hires doctors to examine the worker. The “IME” doctors proclaim that this disrupted disc existed before the worker suffered the bending and lifting injury. Even if it was not diagnosed and treated before the injury, it is part of an “arthritic condition” called degenerative disc disease (DDD). The DDD was present before the injury and the injury combined with it. The IME doctors say that this “preexisting condition” (not the compensable injury) is now the major cause of any disability or need for medical treatment in the worker’s low back. The employer issues a denial to this effect.

Based on the IME report, the employer denies the worker’s current combined condition – the disrupted disc. In order for workers’ compensation coverage to continue for the worker’s low back problems, the worker now needs to appeal the denial and prove that the accepted work injury was the major contributing cause of the disability and need for treatment of this disrupted disc.

Is the work injury (accepted as “low back strain”) the major cause of all the disability and treatment the worker now needs for the disrupted disc?

The worker must present medical opinion evidence explaining why the work injury is the major cause of his ongoing low back problems. The opinion of an attending physician who disagrees with the opinions in the IME is very important. This medical opinion evidence must be more persuasive than the IME report of the employer/insurer-funded doctor(s).

If he cannot present such evidence, the worker loses his compensation for medical treatment and for lost time from work resulting from his low back, treatment of the disrupted disc. The treatment for a disrupted disc, as you know, is usually more extensive and expensive and disabling than for a “strain.” (For a more elaborate typical scenario, see “An Anatomy of a Work Injury to the Spine,” Medical-Legal Journal, Vol. 23, Spring 2003.)

Giving a Major Cause Opinion
When you give a major cause opinion, please be sure you are aware of and account for all other potential causes.

Your opinion should explain the approximate relative contribution of each causal factor (by percentage), and explain why you believe the work injury makes a greater contribution than the total of all the other causes combined, if that is your opinion.

OCCUPATIONAL DISEASE: Major Cause Always Must be Proved

The law defines an occupational disease as

Any disease or infection arising out of and in the course of employment caused by substances or activities to which an employee is not ordinarily subjected or exposed other than during a period of actual employment . . . which requires medical services or results in disability or death, . . .

ORS 656.802(1)(a).

The legal definition includes:

  1. diseases or infections caused by ingestion of,absorption of, inhalation of or contact withdust, fumes, vapors, gases, radiation or other substances;
  2. mental disorders, whether sudden or gradual in onset, … (including physical disorders caused or worsened by mental stress); and
  3. any series of traumatic events or occurrences [such as repetitive work activities, like bending and lifting, which involve repeated insults to a particular body part or parts].

The worker always must prove that the employment conditions were the major cause of the occupational disease.

If the occupational disease is based on the worsening of a preexisting condition, the worker must prove that employment conditions were the major cause of the combined condition and the pathological worsening of the disease.

The law specifically provides that preexisting conditions shall be deemed causes in determining the major contributing cause of an occupational disease.

When you give a medical opinion on whether the work activities or employment conditions were the major contributing cause of an occupational disease, you must account for (state the percentage of) the causal role of all relevant preexisting conditions and non-work causes, as well as the amount of cause attributable to work exposure.

How Has the Preexisting Condition Law Changed?

The alleged preexisting condition now must “contribute to” the disability or need for treatment, not just “predispose” the worker (make the worker susceptible) to disability or need for treatment. The revision eliminated the words “or predisposes” which were in the definition previously.

By eliminating conditions which only predispose or render a worker more susceptible to disability or need for treatment, the legislature is clearly requiring that any alleged “preexisting condition” must contribute in an active causal way to the actual claimed injury.

By eliminating conditions which only predispose or make a worker susceptible to disability or need for treatment, the 2002 law should limit denials based on a worker’s gender, height, obesity, body habitus, type of acromion, shape of wrist, and other peculiar anatomical features. When called upon for an opinion, you should be prepared to state whether preexisting anatomical features mentioned in medical reports actually caused the claimed condition or only made your patient more susceptible to the claimed condition.

Also, the revised definition of “preexisting condition” added the requirement that there must have been diagnosis or medical treatment of the preexisting condition before the claimed work injury, unless the pre-existing condition is arthritis or an arthritic condition. So, the diagnosis and treatment of the alleged “preexisting condition” must have preceded the initial injury, the onset of the new medical condition claimed, or the onset of the worsened condition, in “aggravation” claims.

The requirement of a prior diagnosis or obtaining of medical services for symptoms is significant. If a worker suffers a heart attack on the job and no heart condition had ever been diagnosed or treated, then a heart condition may not, by definition, be considered a “preexisting condition” for purposes of opposing the worker’s injury claim.

The “arthritis exception” keeps alive a favorite defense against back injury claims. Insurer-funded “independent medical examiners” in their “IME” reports insist that degenerative disc disease is arthritis or an arthritic condition, rather than just a normal process universally occurring with age.

Furthermore, it would appear that the revised definition would require that even arthritic conditions which only predispose a worker to disability or make the worker more susceptible to injury not be regarded “preexisting conditions” that weigh against the worker, on the scale of relative contributing causes. Again, your medical opinion is vital on this question.

As to injury claims, the law has now moved the burden of proof to the employer to show a preexisting condition and that the work injury combined with it.

The worker has the responsibility to prove he/she suffered a compensable work injury or occupational disease.

However, if the compensable injury combines with a preexisting condition, the employer has the burden of proving that the compensable injury is no longer the major contributing cause of the disability or need for treatment of the combined condition.

This burden of proof change occurs only in injury claims and does not apply to occupational disease claims.

In summary, since January 2002, the law has tightened the standards for a preexisting condition, 1) by confining it only to those conditions which contribute to the injury or disease; and 2) by requiring its diagnosis or treatment prior to a claimed injury, worsened (aggravated) condition or new medical condition, except when the preexisting condition is an arthritic condition.

Also, the new law codifies court rulings that the employer/insurer is responsible to prove the compensable injury is no longer the major cause in combined condition cases.

Finally, the new law clarifies how injuries and occupational diseases are to be treated differently in preexisting condition situations.

We hope these explanations are helpful to you when you give your medical opinion in cases where your patient’s work injury or occupational disease claim may be threatened by an alleged “preexisting condition.”

This article was prepared by Arthur W. Stevens III and Peter E.

Posted in: Workers' Compensation Lawyer Articles