The Role of Medical Evidence and the AMA Guides in Oklahoma Workers’ Compensation Cases
By Steven E. Hanna

The Oklahoma Workers’ Compensation system is designed to treat and compensate injured workers. This process necessarily merges fact questions of who, what where and why, with medical issues such as causation, the need of treatment, apportionment and work restrictions. Therefore, the practice of workers’ compensation law requires the practitioner to have more than just a passing knowledge of the medical as well as the legal issues.

The lawyer must be able to review treating records and testimony and make decisions regarding whether or not a claim is likely to found compensable; what type of medical expert can best treat or address the medical issues presented; and whether the opinions expressed by the expert are credible and reliable. In order to enable the system to work effectively, the statutory framework provides several tools that relate specifically to the medical issues and evidence needed within this system.

The court classifies medical evidence as either historical or substantive. Historical medical evidence is any medical evidence generated contemporaneously with treatment, which is provided to assist the court in developing an accurate picture of the treatment and condition of the claimant. This evidence can include evidence that may not be admissible to prove the case, such as therapy notes, nurses’ notes, intake sheets, prescriptions, office notes et cetera. While this evidence is not used to prove a prima facie case, it may represent information your medical expert relied upon to reach his conclusions. Substantive medical evidence, however, must comply with all of the rules of the workers’ compensation court and generally takes the form of narrative medical reports.

Due to the volume of cases and the time constraints placed on the system, by attempting to return the injured worker to the workforce as quickly as possible, the court allows medical testimony to be received in an expedited manner.1 Without these considerations, the system would be significantly more costly and burdensome. When a physician testifies by way of a written medical report, specific information is set out in the court rules as to what should be contained in the report.2 While the omission of any one of the recommended items may not be fatal to the admissibility of the report, it may place in question the weight the judge will give to the opinions and conclusions of the doctor. Thus, allowing the opposing party to attack the report as lacking in probative value.

When offering medical evidence to be considered by the court, there are two different types of objections that a party can raise.3 First is a competency objection, which goes to the admissibility of the record or report. A report deemed not to be competent will not be admitted into evidence. When such an objection is sustained, the offering court must give the party an opportunity to cure the defect in the report.4 This effectively prohibits a jackpot-type outcome as a result of some technical error or omission in a medical report.

Another objection that can be asserted as to medical evidence does not affect its admissibility but rather questions the quality of the evidence. A probative value objection merely points out that due to some defect or inaccuracy, the report should be given less weight than other evidence being offered. In some cases, a claimant might have been examined by a number of doctors. Each of those doctors may have surmised whether or not in their opinion the injury was work related. However, if only one of those doctors was aware that the claimant had a prior injury to the same part of the body and addressed that issue in their report, that report would be more helpful than the others. The court might then choose to give additional weight to the report.

Occasionally, the two types of objections can merge into a hybrid. When medical evidence is deemed to be lacking in probative value, it can be rendered incompetent and therefore inadmissible.5 This occurs when the medical evidence is lacking information that is critical to the issues that are in dispute. An otherwise competent report that fails to address whether the worker is physically able to return to his previous employment is of little use to the court to determine if the worker needs vocational retraining.

A narrative report that is in substantial compliance with Rule 20,6 and addresses the issues in dispute, can therefore be admitted and save the court and parties the time and expense necessary to call the physician to testify live. It should be noted that the term physician has been defined in the statute to include a medical doctor, chiropractor, podiatrist, dentist, osteopathic physician, optometrist and a psychologist when requested by the court.7 Assuming we now have a medical practitioner qualified by the statute to testify who has written a report that addresses the issues being reviewed by the court, it is now necessary to review the report to determine if it actually complies with the AMA Guides.

Perhaps one of the least understood issues facing the practitioner of workers’ compensation claims in Oklahoma is the use and application of the appropriate edition of the American Medical Association’s Guides to the Evaluation of Permanent Impairment.8 One of the underlying premises of the Oklahoma workers’ compensation system is to compensate injured workers for the functional loss resulting from an on the job injury. To do so in an objective and consistent manner, the Workers’ Compensation Act mandates that all medical reports addressing the extent of permanent partial disability be in compliance with the AMA Guides.9

Despite this relatively simple mandate, the guides are not utilized in their totality. Rather, entire sections or parts of sections have been carved out as being inapplicable to our system. This incomplete use of the guides creates confusion at first glance, but the departures from the guides in many instances are well founded. An example of this departure is seen when looking at rating spinal impairments.

The AMA Guides fifth edition provides two different methodologies a doctor can use for establishing an opinion of the extent of impairment present. They are the diagnosis related estimate and the range of motion method. While both methodologies are used in other states, only the range of motion method is admissible in Oklahoma workers’ compensation cases.10 Thus, the application of the AMA Guides within the workers’ compensation system can be quite tricky and requires a certain amount of familiarity not only with the guides but also the statutes, rules and relevant cases interpreting their use.

Despite years of experience by many of the medical experts in this field, the reality is that they do not always apply the guides correctly. These mistakes often occur because the doctor did not have a complete or accurate history given to him by the patient. A relatively small change in the medical history, or failure to have reviewed one diagnostic test, can in some instances greatly effect the final impairment determined after applying the guides.

For example, if the examining physician is unaware that the patient had a pre-existing herniated disk at the level in question, documented by an MRI scan, it can possibly lower a rating by as much as 10 percentage points. If that patient is at the maximum rate of compensation, the omission could lower the potential exposure by as much as $13,000. Lapses such as this could occur as a result of a faulty history, inadequate record gathering or review, and sometimes just as a result of an inability to obtain the records in a timely fashion prior to the report being written. But even where all of the records are obtained and reviewed, issues still arise as to how to use and apply the guides on a case-by-case basis.

In addition to errors caused by a lack of information, the lawyer must also be familiar enough with the use of the guides to verify that the respective tables and chapters are applied correctly. The impairment identified may also decrease or increase depending on which version of the guides is used to evaluate an injury. As medical science develops, the guides are constantly re-evaluating the basis upon which their conclusions are founded. New procedures, surgeries and treatments may alter outcomes or functional levels.

In those circumstances, the guides might not have caught up with the science, and the rating of disability resulting from the new treatment, condition or disorder may not be adequately addressed by the guides. The fifth edition of the guides devoted an entire chapter to rating pain as a condition. Previously, the accompanying pain of a condition was rated as a part of the condition. Not all pain can be rated separately but certainly claimants who qualify for such treatment would receive additional impairment.

The doctor must use his experience and knowledge to make such determinations as best he can. Likewise, the guides do allow a doctor to depart or deviate from the guides when a claimant cannot be adequately rated for some reason. The guides require extensive documentation be undertaken to support such a departure, but it can be done. The practicing attorney must be able to spot these deviations and determine whether the doctor has adequately explained the action taken or whether a deposition is warranted, or merely an objection at trial.

For these reasons, it is important to remember that the guides are not intended to be a comprehensive computation that removes all subjectivity. Rather, it is nothing more than the collective concurrence of a group of medical professionals, based on the best science known and understood at the time. It is easy to get lost in the day-to-day practice of workers’ compensation law and develop a false sense that by using the guides we have an objective measure of impairment. The legal system would like the process to be black and white with as little subjectivity as possible, and therefore providing predictable and reproducible results. However, the reality is that the guides, while they are better than having no benchmark at all, fall short of the desired cure-all.

Despite no objective measure of impairment, the competing and sometimes contradictory nature of presented medical evidence, and the problems that can occur in making sure a report has all the necessary information, a new wrinkle has been added by the Legislature. Recent statutory changes regarding the role of the treating doctor make the attorney’s role even more difficult. The new law attempts to require the trial judge to place more weight upon the opinion of the treating doctor, as opposed to that of other expert medical testimony offered.11 The problem created by such a rebuttable presumption is that many treating doctors have little or any knowledge in the application of the AMA Guides.

Even if a treating doctor can rate using the guides, many question the wisdom of having medical specialists gauging their own successes or failures. Beyond the obvious concerns, many doctors have acknowledged that it is simply not a good financial use of their time to conduct a thorough rating evaluation. In the time necessary to perform one proper rating evaluation, a specialist could have seen several additional patients. Additionally, by undertaking the task of rating the extent of disability, the doctor opens the door to having to set aside precious hours of office time to defend his opinions in a deposition.

Beyond the common sense concerns to these changes, there is also a larger potentially constitutional hurdle — the treating doctor could be given additional consideration when comparing their opinions to that of other expert medical testimony. In a recently published opinion by the Oklahoma Supreme Court, the question of arbitrarily giving more weight to one class of medical expert’s opinion was addressed.12

In the Yocum case, the court was addressing the Court of Civil Appeals (COCA) decision that greater weight should be given by the trial court to the opinion of a court-appointed medical examiner than that given to any other medical expert. The COCA seemed to suggest that the mere fact the doctor examined the patient at the request of the court placed a greater import upon his conclusions. The Supreme Court in its opinion rejected this, noting that specific weight to be given to each and every piece of evidence, both factual and medical had to be reserved to the trier of fact. The proper weight could only be established by interacting the testimony with the evidence and observations and conclusions derived from the trial process.

While the court in the Yocum case did not decide specifically whether or not the Legislature could statutorily mandate an increased level of weight to be given to a specific opinion, it articulated some clear indications that such an attempt might not be constitutional. Justice Marion Opala, in his opinion, noted that there was no such clear statutory expression to support the decision of the COCA. However, the opinion goes on to suggest that even if there had been such an attempt, it might be contrary to the separation of powers doctrine, and therefore, unconstitutional.

The Supreme Court noted that such an attempt would amount to “a legislative removal of the discretionary component in adjudicative process is a usurpation of the court’s freedom that is essential to the judiciary’s independence from the other two branches.” The court went on to note that to require the Workers’ Compensation Court to give an increased level or probative value to a specific doctor “…would rob that tribunal of its independent power to establish impairment or disability within the range of received competent evidence.” This rather strong dicta adopted by a majority of the court certainly presents serious concerns for the constitutionality of the new language found in the recently amended §17.

To date, the new language has yet to face appellate scrutiny. Until such a review, we are left to wonder just how many treating doctors will actually attempt to rate permanent disability. Will these treating doctors be able to write a report that meets the requirements of Rule 20 and be in compliance with the appropriate edition of the AMA Guides? Only time will answer how these recent changes may alter the presentation of medical evidence in the near future. The one item that remains clear is that with every change in statute, rule and editions of the AMA Guides, the role of the attorney becomes more difficult.

1. Rule 20 the Rules of the Oklahoma Workers Compensation Court provides, “A. Expert medical testimony may be offered by: 1. A verified or declared written report signed by the physician; 2. deposition; or 3. Oral examination in open court.
2. Rule 20(B) reads, “ The Workers’ Compensation Court recognizing that it is costly and time-consuming to have physicians appear at trial, encourages the production of medical evidence by verified or declared written medical reports. The Court encourages but does not require the report to include the following information, as applicable: 1. A complete history of the claimant, including all previous relevant or contributory injuries with a detailed description of the present injury. 2. The complaints of the claimant. 3. The physician’s findings on examination, including a description of the examination and any diagnostic tests and x-rays. 4. The date and cause of the alleged injury and whether, in the physician’s opinion it is job related. 5. The period during which the claimant was temporarily and totally disabled, and if such temporary total disability has ended, the date on which it ended.
3. Rule 27(C) of the Workers Compensation Court provides in part “… an objection to medical testimony offered by a signed, written, verified or declared medical report, if on the grounds that it: (1) is based on inaccurate or incomplete history or is otherwise without probative value, or (2) does not properly evaluate claimant’s impairment or disability, as the case may be, in accordance with the Workers’ Compensation Act, …”.
4. Rule 27(e) of the Rules of the Oklahoma Workers’ Compensation Court requires that they “offering party may elect to either stand on the evidence or be given a chance to cure the defect.”
5. The party making the objection usually will object both to the competency and probative value of the report, advising the court that the errors or omissions contained in the proposed evidence are critical to the issues before the court, and that the error or omission makes the evidence so unreliable as not to be admissible.
6. It is not necessary that a medical report be perfect, that the doctor reviewed every medical record or was aware of every fact. The court uses its fact-finding authority to determine if the evidence is based on enough of the information available to make it reliable. That is not to say that a report lacking any fact is not subject to the probative value objection already discussed.
7. 85 OS§ 20(E)
8. Pursuant to Court Rule 21 the applicable edition depends on the date of accident. Before July 1, 1978 the Guides were not used, instead the ability to perform “ordinary manual labor” standard was utilized. Beginning in 1978 various editions have been used. Currently in use since June 28, 2001 is the 5th edition of the Guides.
9. Rule 21 of the Rules of the Oklahoma Workers’ Compensation Court states, “Except as provided in Rules 22 and 23 a physician’s evaluation of the extent of permanent impairment SHALL be prepared in compliance with the appropriate edition of the AMA Guides to the Evaluation of Permanent Impairment, including approved deviations and exceptions as set forth in this rule.”
10. Rule 21 F
11. 85 OS§ 17 (A)(2)(a) “ There shall be a rebuttable presumption in favor of the treating physician’s opinions on the issues of temporary total disability, permanent disability, causation, apportionment, rehabilitation or necessity of medical treatment.”
12. Vicki (Root) Yocum v. Greenbriar Nursing Home, 2005 OK 27, 130 P3d 213.

About the Author

Steven E. Hanna practices primarily in the area of workers’ compensation insurance defense. He received his undergraduate degree from East Central University and his J.D. from the University of Tulsa College of Law. He is a frequent speaker on issues within the workers’ compensation system and represents a variety of employers and third-party administrators, as well as insurance companies and own risk employers.

The Role of Medical Evidence and the AMA Guides in Oklahoma Workers’ Compensation Cases Published 77 OBJ 2753 (Oct. 7, 2006)