Source: Journal of Chronic Fatigue Syndrome Vol. 14, #2, pp 7-23 Date: Summer 2007
Legal and Scientific Considerations of the Exercise Stress Test
Margaret Ciccolella, EdD, JD; Staci R. Stevens, MA; Christopher R. Snell, PhD; J. Mark VanNess, PhD - Margaret Ciccolella, Staci R. Stevens, Christopher R. Snell, and J. Mark VanNess are affiliated with the University of the Pacific, Pacific Fatigue Laboratory, Stockton, CA. - Address correspondence to: J. Mark VanNess, University of the Pacific, Stockton, CA 95211 (E-mail: firstname.lastname@example.org ).
This article examines the legal and scientific bases on which an exercise stress test can provide medically acceptable evidence of disability for the Chronic Fatigue Syndrome (CFS) patient. To qualify for disability benefits, a claimant must establish the existence of a serious medically determinable impairment (MDI) that causes the inability to work. The single stress test has been used to objectively establish whether a claimant can engage in "substantial gainful employment" and is an important determinant of the award or denial of benefits. A review of case law indicates problems associated with a single test protocol that may be remedied by a "test-retest" protocol. The results of a preliminary study employing this approach indicate that the test-retest protocol addresses problems inherent in a single test and therefore provides an assessment of CFS related disability consistent with both medical and legal considerations.
Denial of Benefits: Typical Scenario
Denial of related disability benefits is a common problem for the patient with a medical diagnosis of Chronic Fatigue Syndrome (CFS). The typical scenario can be described as follows: Debilitating fatigue prevents continued work and the CFS patient reports the diagnosis to his or her employer. The patient becomes a "claimant" upon application for related disability benefits from the Social Security Administration (SSA) and/or a private insurance carrier. The initial burden is on the claimant who must objectively establish the existence of a medically determinable impairment (MDI) that is serious enough to cause the inability to engage in any "substantial gainful employment." Claimant fails to provide sufficient objective evidence and disability for the inability to work is successfully challenged resulting in the denial of benefits. Appeals are available but the burden rests with the claimant to pursue a reversal of the denial.
At the appeal and regardless of the agency involved, a review of the medical record fails to provide sufficient objective evidence of a serious impairment that causes disability. While the diagnosis is accepted, the central legal issue is whether the claimant can work on a regular and ongoing basis.The medical record documents that the diagnosis is largely based on self-reports by the patient to the treating physician and that the symptoms upon which a diagnosis or MDI is made overlap with other illnesses. This makes it difficult to distinguish CFS from other illnesses. It is undisputed that there is no widely accepted definitive laboratory test for CFS. However, the record used to objectively document a FRC that precludes the ability to work on a regular and ongoing basis includes a single exercise stress test. The test shows diminished metabolic capability consistent with the ability to do at least sedentary work and the benefits are denied.
Problem: The Single Stress Test
The single stress test has been utilized to assess Function Residual Capacity (FRC) and therefore determine whether a claimant can work. The problem is that a review of case law documents that both good and poor results of a single stress test have been used to deny benefits. A good result contradicts the diagnosis of disability because it appears to show the ability to work. A poor result is subject to the criticism that the claimant malingered by deliberately failing to exert maximal effort on the test.
It is our position that utilization of a single test fails to objectively establish disability from both a legal and clinical perspective. We premise this paper on the assertion that "post-exertional malaise" is the cornerstone symptom of CFS related disability. The objective assessment of the fatigue suffered following a test is critical to the determination of ability to work on a regularand ongoing basis. Such an assessment requires integration of law and science if meaningful consequences are to result for the CFS patient.
SSA explicitly states that continued research will produce new evidence to "clarify the nature of CFS and provide greater specificity regarding the clinical and laboratory diagnostic techniques that should be used to document this disorder" (1). The purpose of this paper is to explore the utilization of a "test-retest" protocol consistent with such a mandate. The legal considerations relevant to the use of a single stress test protocol will be discussed followed by a report of preliminary "test-retest" research conducted at the Pacific Fatigue Laboratory.
Social Security Administration (SSA) Policy
Social Security Ruling (SSR) 99-2p (1999) Mettlen v. Commissioner of the SSA (2003)
Social Security rulings constitute general policy statements but they do not have the full force and effect of law. While SSA rulings are not binding upon a court, courts in fact frequently rely upon them. This reliance is evident in a review of appeals denying benefits involving both SSA and private insurance companies. For this reason, SSA policy for evaluating CFS disability claims is briefly reviewed here.
SSA accepts the definition of CFS established by an international group convened by the Centers for Disease Control and Prevention (CDC). Under the CDC definition, the hallmark of CFS is the presence of clinically evaluated and debilitating chronic fatigue that cannot be explained by another physical or mental disorder. SSA requires a dual process in the establishment of CFS disability in that a claimant must prove (1) the existence of a "medically determinable impairment" (MDI) and (2) the inability to engage in any substantial employment.
1. Establishing the MDI. Physicians sometimes cannot make a conclusive diagnosis of CFS and there is no "dipstick" laboratory test for diagnosing the condition. SSA accepts the symptom-based criteria for the diagnosis of CFS established by the CDC,1 but requires a strict timeline for the concurrence of at least four symptoms that include post-exertional malaise lasting more than 24 hours. Of the listed symptoms, post-exertional malaise is considered to represent the cornerstone symptom of CFS and is therefore is especially relevant to this paper.
While diagnosis may be based primarily on self-reported symptoms, disability requires objective evidence. For example, SSA policy explicitly disallows a finding of disability based solely on subjectively allegations of symptoms or impairments. A serious impairment (MDI) must be objectively proven. Since the medical community has not reached agreement on a definitive test, SSA allows reliance on "certain" listed laboratory findings to establish the existence of the MDI.2 The list of enumerated laboratory findings includes "an abnormal stress test" using a "medically accepted" protocol.
2. Establishing the ability to engage in any substantial employment. SSA policy considers whether a claimant has the ability to engage in "substantial gainful employment," i.e., whether the claimant can sustain work-related activities in a work setting on a regular and continuing basis. Residual functional capacity (FRC) laboratory test assesses whether the claimant, in spite of a serious impairment, has the physical and mental ability to perform activities required by competitive, remunerative work. If an applicant's FRC fails to meet the requirements of regular, previous employment, then the burden is on the Commissioner to show that the claimant can do work as it is generally performed in the "national economy" (Mettlen v. Commissioner of the SSA, 2003).
Examples of Appeals Using the Exercise Stress Test
The most common use of the stress test in appeals is to objectively establish FRC and work capacity by assessing the metabolic onset of fatigue. A single stress test is ineffective in establishing a MDI because it cannot document post-exertional malaise, a cornerstone symptom used to diagnose CFS, and does not distinguish between CFS and other illnesses. It further fails to effectively assess disability in that both good and poor performances have been used to dispute an inability to work and deny benefits. The following cases illustrate the problems when a single stress test protocol is used.
Problems Associated with a Good Result on a Single Stress Test
O'Sullivan v. The Prudential Insurance Co. of America (2002) Marshall v. Sullivan (1990)
In O'Sullivan v. Prudential (2002), the former director of human resources in a New York City hotel (claimant) appealed a private insurance company's denial of long-term benefits. Prudential discontinued the long-term disability benefits after claimant, a CFS patient with overlapping symptoms of fibromyalgia, alleged total disability. Prudential had the medical records of the claimant reviewed by a consulting physician asking her to answer two specific questions: (1) what objective medical evidence existed that rendered claimant unable to perform the sedentary duties of her job and (2) based on the medical evidence in the record, did the claimant have any restrictions or limitations of her functional ability?
The response to both questions focused in part upon the results of a single exercise stress test in which the claimant's relatively good performance appeared to demonstrate the ability to work. With regard to claimant's ability to work, Prudential's consulting physician concluded that no objective evidence existed to support claimant's inability to perform a sedentary desk job. "She was able to reach 9 METs of exercise on a stress test... more than what is generally considered minimally necessary for a sedentary job." With regard to functional ability, the physician stated that "very little documentation of [claimant's ] actual physical abilities is available in the medical records... The treadmill test documented that she is able to walk uphill for nearly 8 minutes at a time..."
During the proceedings, Prudential did not contest claimant's complaints of pain and fatigue or the fibromyalgia diagnosis. Instead, Prudential simply maintained that there was no objective medical evidence which established how the claimant's condition rendered her totally disabled.
The court addressed the question of disability by considering two issues: (1) whether claimant was unable to perform the duties of her job due to sickness and (2) whether the claimant was unable to perform the duties of any job consistent with her education, training, or experience. The court found the record devoid of any evidence that the claimant's treating physicians were aware of the duties of the claimant's job [**]and further concluded that they were apparently ignorant of her level of education, training, and experience. The court found that the claimant's treating physicians offered "little more than conclusionary assertions that do not establish that [claimant] is totally disabled." Here, while claimant was granted SSA benefits, Prudential's denial of long-term benefits was upheld.
In Marshall v. Sullivan (1990),3 claimant appealed SSA denial of benefits for chronic fatigue. Claimant was a 68-year-old accountant for the state of Virginia who was initially diagnosed with chronic infectious mononucleosis related to Epstein-Barr virus (EBV). Her treating physician concluded that she was totally disabled based upon her reports of debilitating fatigue following routine exertion and lab results showing persistent elevation of EBV antibody titers. It should be noted that by the end of her appeal EBV and mononucleosis were ruled out as causing disability and the proper diagnosis of Chronic Fatigue Immune Dysfunction Syndrome (CFIDS) was made.
In addition to her treating physicians, three additional physicians examined claimant (one each from SSA, a private insurance carrier, and the state retirement board) and all agreed that claimant was disabled. The only report to contradict claimant's disability came from the medical advisor for SSA who neither treated nor examined claimant. According to the medical advisor, the results of the treadmill test revealed a lack of disability and he found that claimant had the capacity "for at least light work." The claimant's high level of performance on the treadmill proved that she had the "residual functional capacity" to work comfortably at lower levels of activity. The Administrative Law Judge (ALJ) relied primarily on the medical advisor's opinions and the results of the treadmill test in finding claimant not disabled.
At the appeal, the ALJ was found to have improperly analyzed claimant's fatigue.
In his decision, the ALJ refers to that test [treadmill test] as `an objective tool by which the Administrative Law Judge can measure the claimant's fatigue.' This is clearly not the case; Marshall's [claimant's] performance on the treadmill revealed nothing about the increased fatigue she suffered following the test.
It was determined that the treadmill test failed to provide persuasive evidence to contradict the treating and examining physicians. Therefore, the SSA decision to deny benefits was reversed and claimant was awarded benefits. While the outcome was good for the claimant in this particular case, the risk and burden on the claimant was clear. The objective results of a single test resulted in an initial denial of benefits and the claimant was forced to pursue two appeals in order to ultimately prevail. This might have been avoided altogether had the claimant participated in a second test to objectively document the fatigue that she suffered following the first test. See discussion below.
Problems Associated with a Poor Result on a Stress Test
Coffman v. Metropolitan (2002)
In Coffman v. Metropolitan (2002), claimant appealed the denial of long-term benefits from a private insurance company. Claimant worked as a drug representative for a major company and was subsequently diagnosed with CFS, hypothroidism, vertigo, and other conditions. Metropolitan denied disability benefits claiming the medical record had "insufficient objective clinical findings" to support claimant's subjective complaints and did not support that [claimant] was "unable to perform the duties of his job." Further, Metropolitan offered expert testimony that the fatigue of a chronic nature experienced by claimant was more likely due to other conditions.
At trial, claimant offered the results of a cardiopulmonary stress test to prove a significant impairment of functional aerobic work. Claimant's treating physician stated that maximal oxygen consumption was only 61% of predicted for sedentary individuals and that this poor performance showed the inability of claimant to "sustain work."
Metropolitan responded that these conclusions were wrong because they were based on "a test which clearly revealed less than maximal effort" noting that claimant reached only 73% of his predicted maximal heart rate. Claimant's treating physician responded to the criticism asserting that claimant was on cardiac drugs (calcium channel blockers) that may have blunted heart rate and that excellent effort on the test was observed in blood pressure readings that increased from 120/80 to 200/94 and increases in oxygen pulse and respiratory rate. He further stated that hyperventilation due to anxiety accounted for a respiratory quotient (RQ) greater than one at the beginning of the test.
Metropolitan used video-surveillance showing claimant running errands with his wife, driving a car, attending church, carrying two tote bags, etc. This direct observation of claimant's activities was effectively used to contradict the claim that physical limitations precluded work and provided additional support for Metropolitan's challenge to the results of the stress test. A Metropolitan expert testified that claimant's functional capacities were "compatible with the Department of Labor Work Category definition of light to medium work." The shadow cast upon the results of the stress test and the lack of objective medical evidence to support disability resulted in a ruling that upheld Prudential's denial of benefits.
[** Similarly, one of my doctors stated unequivocally that I could work without having any clue about my job duties; on questioning, he seemed to think my function was purely decorative with no production necessary. He had received a one-page typed letter from me and without knowing who wrote it or who typed it, relied on that to say that I could work successfully. Doctors who saw me sit up for 5 minutes stated unequivocally that I could sit for 8 hours, without any proof that their extrapolation was accurate. I've never had a Residual Functional Capacity Evaluation that proved I could work for 8 hours in one day; they don't want to develop the proof that I'm telling the truth, and rely on the fact that I cannot afford to pay for such testing myself ... only to have it rejected by the judge on the assumption that a poor result could only mean malingering, as described above]