Dr. Groopman provides an excellent overview of the subject of fatigue in cancer and HIV/AIDS patients and highlights the many reasons why this symptom has frequently been overlooked and undertreated by both physicians and other health-care providers. Concurrent with the greater appreciation of fatigues prevalence rates in cancer and HIV/AIDS patients and its negative impact on quality of life (QOL)[1,2] and, potentially, on mortality, more concerted efforts have been made to develop, test, and evaluate methods that will better assess and treat fatigue clinically to improve patient-related outcomes.
Although Dr. Groopman is accurate in stating that currently there is no universal definition for fatigue, there is a growing consensus among health-care providers and fatigue scientists on the following points:
1) In clinical states, such as cancer and HIV/AIDS, fatigue is a subjective, multidimensional sensation similar to pain, which is best measured by self-report.
2) Fatigue is the perception of an unusual or debilitating sense of whole-body tiredness, as distinct from the usual sense of tiredness experienced by healthy individuals.
3) Fatigue is multifactorial, suggesting that fatigued patients may benefit from the use of multimodality therapies as well.[3,5]
Incorporating Fatigue Assessments Into Clinical Practice
Despite the existence of numerous scales to measure the perception of fatigue, fatigue assessments have not been incorporated routinely into health-care settings, as has been the case for pain assessments, for the many reasons mentioned by Dr. Groopman. In addition, many of the current self-report scales that measure fatigue have been developed and tested primarily in research settings and have not been designed for or tested in clinical settings.
For fatigue scales to be used in busy practice settings, not only they must be valid, reliable, and sensitive to measuring change over time, but also they must be easy to administer and to score, and should not cause fatigue or unduly burden the subject in the process. As Dr. Groopman mentions, this is an area of intense investigation, and at least three studies have been funded recently by the Oncology Nursing Foundation/OrthoBiotech Fatigue Initiative Through Research and Education Project (FIRE) to develop, test, and evaluate more clinically relevant fatigue scales in adult and pediatric oncology patients.
As mentioned in the Groopman article, however, fatigue has been measured unidimensionally, by single-item intensity scales, such as the Rhoten Fatigue Scale; by multiple-item intensity scales that stand alone as scales, such as the Pearson-Byars Fatigue Feeling Tone Checklist; or by subscales imbedded in existing scales designed to measure other phenomena, such as the Sickness Impact Scale, the Functional Assessment of Cancer Therapy (FACT)-Fatigue Scale, and the Profile of Mood States Fatigue-Inertia subscale. Since symptom intensity often drives treatment decision-making, measuring fatigues intensity by using a simple 11-point numeric rating scale, such as 0 = no fatigue to 10 = overwhelming fatigue, or by employing any of the previously mentioned scales may be helpful to incorporate into clinical settings.
As all cancer patients as well as HIV/AIDS patients now are recognized to be at risk for fatigue, it is strongly recommended that all patients be screened routinely for this symptom at diagnosis, and that they be rescreened periodically for its presence. Busy health-care providers can ask patients three simple questions(1) Are you experiencing any fatigue? (2) If yes, how severe is the fatigue on an 11-point rating scale? and (3) How is the fatigue interfering with activities of daily living?to assess the severity of the fatigue for that individual.
As we have discovered with pain measurement, however, intensity alone may be insufficient to measure fatigue. Other methods must be used to capture its multidimensional properties. Although no consensus exists as to what constitutes fatigues many dimensions, fatigue has been measured multidimensionally by several instruments, including the 22-item Piper Fatigue Scale mentioned by Dr. Groopman.
Not all cancer or HIV/AIDS patients may need an in-depth, multidimensional clinical assessment, however. In this era of managed care, it is critical to begin to identify those individuals who are at high risk for fatigue in order to tailor resources and therapies accordingly. A rating of 5 or more on an 11-point scale may be a useful indicator for identifying those patients who require this more in-depth clinical assessment and management of their fatigue.
Multifactorial Nature of Fatigue
Since fatigue is likely to be multifactorial, Dr. Groopman categorizes proposed causes and/or correlates of fatigue into physiologic, psychologic, and situational categories. Although these categories are not mutually exclusive, which is a common limitation of other published models as well, viewing fatigue in this fashion is helpful, as it permits health-care providers to identify and target therapies to the primary underlying cause(s) of the fatigue in individual patients. For example, when such symptoms as pain or insomnia may be contributing to or causing the fatigue, effective symptomatic management may indirectly benefit and treat fatigue as well.
In addition, as signs and symptoms of fatigue can be influenced by the underlying cause(s) of fatigue (similar to the way that disease manifestations vary according to underlying etiologies), this, too, will influence not only how but also when fatigue is measured. For example, the FACT-Anemia scale, described by Dr. Groopman, could be used to assess fatigue at baseline, when patients are beginning to receive treatment anticipated to cause anemia-related fatigue. This scale could be repeated over time to rescreen patients at intervals, particularly when anemia is anticipated to occur, and to measure fatigue-related outcomes to evaluate the efficacy of anemia treatment. Should fatigue be caused by a combination of factors, a more generic, multidimensional fatigue scale might be indicated to assess fatigue and its treatment-related outcomes.
Depression and Fatigue
As Dr. Groopman mentions, it is important to remember that many of the somatic symptoms of depression often overlap with the somatic symptoms of cancer and HIV/AIDS. Since most depression inventories contain both somatic and cognitive/affective items to diagnose depression, false-positive results can occur when these inventories are used in these disease states.[2,10,11]
For this reason, Kalichman and colleagues recommend that, in HIV/AIDS patients, it is appropriate to use depression inventories to screen for and diagnose depression during the early stages of HIV infection when patients have no symptoms caused by HIV. In HIV-symptomatic patients, these authors recommend that the depression inventorys cognitive/affective items/subscales initially be used alone for screening purposes.
A negative result would rule out depression, whereas a positive result would suggest it. Positive findings should be followed by administration of the inventorys somatic items/subscale. A positive result on the somatic items/subscale alone is insufficient to make the diagnosis of depression, however. Similarly, in cancer patients, Visser and Smets documented different patterns of fatigue and depression over time in radiation therapy patients when depression was assessed using the nonsomatic items of the Center for Epidemiological Survey for Depression Inventory (CES-D).
In summary, managed care has been designed to reduce variations in practice in an attempt to maintain and improve quality-related outcomes and reduce costs. Variations in practice can lead to suboptimal care for cancer and HIV/AIDS patients who are fatigued, either because the fatigue is not assessed clinically or it goes untreated. Dr. Groopman has performed a much-needed service by identifying many of the advances that have been made in the assessment and management of fatigue. It is now up to every physician and health-care provider to incorporate these advances into their practice settings to improve the care delivered to the many cancer and HIV/AIDS patients suffering from this debilitating symptom.